- Email: [email protected]
Setting maternity care standards for women with obesity in pregnancy
Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
Contents lists available at ScienceDirect
Seminars in Fetal & Neonatal Medicine journal homepage: www.elsevier.com/locate/siny
Setting maternity care standards for women with obesity in pregnancy Kate J. Fitzsimons a, *, J. Modder a, b a b
Centre for Maternal and Child Enquiries, Chiltern Court, 188 Baker Street, London NW1 5SD, UK UCLH NHS Foundation Trust, 250 Euston Road, London NW1 2PG, UK
s u m m a r y Keywords: Body mass index Guideline Management Obesity Pregnancy
Obesity is associated with an increased risk of pregnancy-related complications that affect both the mother and baby. National clinical care guidelines have been developed by the Centre for Maternal and Child Enquiries, as part of its Confidential Enquiry into Maternal and Child Health (CEMACH) programme. These guidelines are intended to minimise and manage the risks associated with maternal obesity, and they were developed using formal consensus methods based on the Delphi technique. A multidisciplinary group of 25 members participated in the iterative process. Standards of care were based on the best available evidence and expert clinical knowledge and experience. This article describes the process used to develop standards of maternity care for women with obesity, and the resulting recommendations are presented. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction The worldwide prevalence of obesity has increased markedly over the past few decades, with the World Health Organization describing this trend as a ‘global epidemic’ posing a serious threat to public health.1 The increasing prevalence of obesity among women of childbearing age is of particular concern as obesity in pregnancy carries significant additional risks for both mother and baby.2 Obesity in pregnancy is widely defined as a maternal body mass index (BMI; kg/m2) of 30 at the time of the first antenatal consultation. At present, no national-level data on the prevalence of obesity in pregnancy are available in the UK. In 2002–2004, two observational studies reported maternal obesity prevalence rates of 16% and 18% respectively in the North East region of England3 and at a maternity unit in Glasgow;4 however, the prevalence of obesity in the general population has continued to increase since that time,5 which presupposes an increasing prevalence in the general maternity population also. Maternal obesity is now considered one of the most commonly occurring risk factors in obstetric practice, and obstetricians and midwives are increasingly faced with caring for women who are obese. Compared to women with a healthy prepregnancy weight, pregnant women with obesity are at increased risk of miscarriage,6 gestational diabetes,7 pre-eclampsia,8 venous thromboembolism,9,10 induced labour,11 caesarean section,12 anaesthetic complications13,14
* Corresponding author. Tel.: þ44 207 467 3231; fax: þ44 207 486 6543. E-mail address: [email protected] (K.J. Fitzsimons). 1744-165X/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.siny.2009.09.004
and wound infections,7 and they are less likely to initiate or maintain breastfeeding.15 Babies of obese mothers are at significantly increased risk of stillbirth,16,17 congenital anomalies,18 prematurity,19 macrosomia7,11,20 and neonatal death.17,20,21 Intrauterine exposure to maternal obesity is also associated with an increased risk of developing obesity and metabolic disorders in childhood.22 It is clear that women with obesity pose particular management problems relating both to the increased risks of specific complications in pregnancy, as well as the medical, surgical and technical challenges in providing safe maternity care. Despite these welldocumented problems, there is currently no national clinical guideline available in the UK with regard to the clinical care and provision of services for women with obesity in pregnancy. In 2008, the Confidential Enquiry into Maternal and Child Health (CEMACH), now known as the Centre for Maternal and Child Enquires (CMACE) commenced a three-year national Obesity in Pregnancy project as part of its CEMACH programme. This project was initiated in response to a number of factors, including: (i) growing evidence that obesity is clearly associated with increased morbidity and mortality for both mother and baby, (ii) unknown national and regional prevalence rates, and (iii) the absence of a national clinical guideline available in the UK. The project comprises three phases, as shown in Box 1. One of the key objectives of the CMACE project was to develop recommendations to guide clinical care aimed at minimising complications in this high risk group of women, and ultimately help to improve pregnancy outcomes. While clinical recommendations should be derived from the highest level of research evidence available, it is recognised that in practice there may be particular areas where there is a dearth of evidence on which to formulate
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
Box 1. Phases of the Centre for Maternal and Child Enquiries (CMACE) Obesity in Pregnancy Project Phase 1 A national survey investigating how well maternity units are equipped to care for women with obesity Phase 2 The development of national standards of care based on evidence and consensus expert opinion Phase 3 A national audit of care provided to women with body mass index 35
recommendations. In these circumstances, it is necessary to develop recommendations based on a robust process gathering together expert opinion and experience. Formal consensus methods offer a means of synthesising and collating a number of individual judgements. Such techniques are increasingly being employed in the development of guidelines in the health sector, in situations where there is a relatively limited evidence-base for practice.23 One of the most commonly used formal consensus methods is the Delphi method (also sometimes known as the Delphi technique), which offers a way of systematically collecting and aggregating informed judgements from a group of experts on a specific topic24 and is particularly suitable for developing clinical guidelines when there is limited research evidence.25,26 Key features of the method include: (i) the use of expert opinion, (ii) a number of iterative questionnaire ‘rounds’ in which members score items, (iii) the quantitative analysis of scores which is fed back to the group, together with any qualitative comments that accompanied the scores, (iv) the opportunity for group members to modify their responses in light of the group feedback from the previous round, and (v) the anonymity of the experts’ responses from each other. One of the main advantages of the Delphi method is that the process can be performed without the need for repeated physical meetings by group members. The CMACE obesity in pregnancy project utilised a modified Delphi approach to develop standards of maternity care for women with obesity, and the specific methodology and resulting final standards are described in this article. 2. Standards of maternity care for obesity in pregnancy outside of the UK A search was carried out to identify guidelines published by recognised professional organisations for the management of obesity in pregnancy. There is currently limited guidance on the range of issues associated with maternal obesity. The Scottish Intercollegiate Guidelines Network (SIGN) Guideline No. 8 (1996) on Obesity recommended that weight loss should be avoided around the time of conception and during pregnancy, although it also stated that limiting weight gain to 6 kg instead of the more usual 12 kg may be advisable in order to avoid co-morbidities such as gestational diabetes and pre-eclampsia.27 The Clinical Practice Guideline on Obesity published jointly in 2004 by the Singapore Ministry of Health and Singapore Association for the Study of Obesity recommended that bariatric surgery should not be performed during pregnancy, that women of childbearing age should practice secure contraception during the period of rapid weight loss following bariatric surgery, and that adjustable gastric bands should be deflated during pregnancy to allow for ‘normal weight gain’.28 The most detailed guidance to date was published in an American College of Obstetricians and Gynaecologists Committee Opinion paper in September 2005. This paper reviewed the evidence for adverse outcomes in pregnancy, such as pre-eclampsia, gestational diabetes, a high caesarean section rate and difficult anaesthesia, and made a number
101
of recommendations, including the need to record maternal height and weight at the first prenatal visit, encouraging an exercise programme during pregnancy, screening for gestational diabetes, the importance of antenatal anaesthetic review, and consideration of surgical techniques to minimise operative complications.29 3. Methodology for developing standards of maternity care for women with obesity in pregnancy in the UK The methodology used by CMACE to develop standards of care included searching for and preparing scientific evidence, consulting with stakeholders, establishing an expert multidisciplinary group, and facilitating the development of standards of maternity care through a formal consensus process. 3.1. Preparation of scientific evidence A review of the literature was performed electronically through Medline, Embase and the Cochrane Database of Systematic Reviews. Search terms relating to obesity, pregnancy, services and interventions were restricted to the titles of English language articles that were related to humans, and had been published in the previous 10 years. Articles were selected if they: (i) related to general care issues for pregnant obese women, (ii) focused on the management of obesity or obesity-related complications in pregnancy, or (iii) focused on the relationship between maternal BMI and pregnancyrelated outcomes. A list of articles meeting the selection criteria was reviewed by the CMACE Obesity Project’s External Advisory Group (a multidisciplinary group of nine senior health professionals with expertise in pregnancy and obesity). Any additional references recommended by the external advisory group were located and assessed according to the criteria above. All articles that met the selection criteria were organised into categories. Tables of evidence were created from the articles which described the type of study and key findings. Each article identified by the initial search criteria was examined to assess its suitability for inclusion in the evidence tables. Box 2 shows the inclusion and exclusion criteria that were used to assess each article.
Box 2. Article inclusion and exclusion criteria for tables of evidence Inclusion criteria Meta-analyses Intervention studies (including randomised controlled trials, randomised trials and controlled trials) Observational studies (including prospective, retrospective, cross-sectional) Cross-sectional surveys Systematic reviews Exclusion criteria Narrative reviews (excepting anaesthesia) Case reports Comments/letters
3.2. Stakeholder consultation Organisations representing healthcare professionals, researchers or patients with an interest in the area of obesity in pregnancy were invited to participate in a consultation exercise. A total of 44 stakeholder organisations were invited to suggest aspects of care or service provision that should be covered by the consensus
102
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
standards. Twelve stakeholder organisations responded during the four-week consultation period. After collating and aggregating the responses, a total of 30 broad areas of care were identified and subsequently presented to the Consensus Standards Group (see below) for consideration.
Consensus Standards Group (CSG) convened
Stakeholder consultation
Literature review and tabulation of evidence
Tabulated evidence sent to CSG
3.3. Establishing a multidisciplinary consensus standards group First CSG meeting
A multidisciplinary group of experts (Consensus Standards Group, CSG) was convened. The group consisted of 25 members who represented a range of disciplines relevant to obesity and pregnancy (see Box 3). The group included two lay representatives with personal experience of obesity and pregnancy. Of the 25 members, six were nominated by UK Royal Colleges representing major professional stakeholders: the Royal College of Anaesthetists (RCA), the Royal College of General Practitioners (RCGP), the Royal College of Midwives (RCM), the Royal College of Obstetricians and Gynaecologists (RCOG), the Royal College of Physicians (RCP) and the Royal College of Paediatrics and Child Health (RCPCH).
Questionnaire developed around agreed areas for standards
Phase 1
Open-ended questionnaire (1) circulated to CSG for suggested standards of care
Responses categorised into common themes and used to construct a series of statements
List of statements [questionnaire (2)] circulated to CSG for feedback on wording
Statements edited according to feedback
Box 3. Disciplines represented by the multidisciplinary group responsible for developing national standards of maternity care for women with obesity
Revised questionnaire (2) circulated to CSG for members to score each Phase 2
standard on a scale of 1–5 for importance and feasibility, and provide comments to justify score
Anaesthesia Dietetics Endocrinology General practice General medicine Manual handling Midwifery Neonatology Obstetrics Physiotherapy Public health Ultrasonography
Individual scores and comments collated, anonymised and added to questionnaire.
Phase 3
Questionnaire (2) with collated scores and anonymised comments circulated to CSG for members to re-score standards where consensus was not reached
Final scores analysed to determine standards where consensus was reached for inclusion or exclusion
Phase 4
3.4. Consensus process
Second meeting to discuss and achieve consensus on outstanding standards
Final consensus standards drawn up
Tables of evidence and the proposed process for developing standards were sent to all CSG members in advance of the first meeting. During the meeting, the group was required to agree: (i) the broad areas for the standards, (ii) the iteration process for achieving consensus, and (iii) the scoring system to include or exclude standards. The process of developing the standards using a modified Delphi approach is illustrated in Fig. 1.
Final standards circulated to CSG for members to suggest any re-wording of standards
Final standards edited according to feedback
Levels and grades of evidence assigned based on the research evidence cited by the CSG in support of each standard
3.4.1. First iteration Shortly after the first meeting, an electronic open-ended questionnaire was emailed to the CSG. Members were asked to submit draft standards within their area of expertise, together with the rationale for the standard and citations of the supporting evidence. A total of 498 standards were suggested by the group. All suggested standards were analysed qualitatively by a researcher and senior clinician based at CMACE. This analysis involved sorting and categorising the proposed standards according to common themes. Many suggested standards overlapped significantly, and once duplicates had been removed there were a total of 198 possible standards. These were then edited in-house by CMACE. The CSG was given the opportunity to suggest any essential rewording prior to the second iteration.
Edited standards and provisional levels and grades of evidence circulated to Phase 5
CSG, for logging of agreement/disagreement and suggestion of alternative levels and grades if necessary
Responses collated and levels and grades of evidence revised as appropriate based on the best available evidence
Final standards reviewed by Obesity Project External Advisory Group Fig. 1. Process for developing the standards of maternity care for women with obesity: the modified Delphi method.
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
3.4.2. Second iteration The second questionnaire sent to the Consensus Standards Group included each of the 198 suggested standards from Round 1 as well as members’ supporting rationales and references. Group members were requested to: (i) score each standard on importance and feasibility, (ii) provide the rationale for their scores, (iii) consider auditability of the standard, and (iv) consider the most appropriate BMI cut-off for specific standards. Importance and feasibility scoring was on a 5-point scale (Box 4). Members had the option of not scoring if they considered that they lacked sufficient knowledge of the area.
Box 4. The 5-point scale used for scoring standards on importance and feasibility Importance scale 1. Not at all important 2. Slightly important 3. Moderately important 4. Very important 5. Extremely important X. Unable to score due to insufficient knowledge Feasibility scale 1. Not at all feasible 2. Slightly feasible 3. Moderately feasible 4. Very feasible 5. Extremely feasible X. Unable to score due to insufficient knowledge
Members of the group were asked to score standards for importance based on their potential clinical impact and the level of available evidence. Scores for feasibility were given according to the likelihood of successful implementation of the standard. Responses to the second iteration were analysed quantitatively to determine whether consensus had been reached. Consensus was defined as 80% of responses occurring within two adjacent scores (e.g. 80% scoring 4 or 5). It was agreed by the group in advance that if 80% of members scored a standard highly (4 or 5), and there were no outliers (scores of 1 or 2), the standard would be automatically included. If 80% scored a standard poorly (1 or 2), and there were no outliers (scores of 4 or 5), the standard would be automatically excluded. Standards meeting the automatic inclusion or exclusion criteria at the end of the second iteration were removed from the subsequent scoring round. Standards not meeting the inclusion or exclusion criteria were rescored by members in the third iteration. A minimum of five members were required to score each standard. Standards without a minimum of five scores remained in the process, regardless of the distribution of scores. 3.4.3. Third iteration The third questionnaire sent to the CSG included bar charts showing the distribution of importance and feasibility scores from the second iteration. Comments made by members to support each importance score were anonymised and made available to the whole group. Individual scores were fed back to those who had submitted them so that members were able to review their own scores in comparison to all responses. A list of the standards meeting the inclusion and exclusion criteria was also provided. For those standards that did not meet the inclusion or exclusion criteria after the first scoring round, members were requested to:
103
(i) re-score each standard on importance and feasibility, (ii) provide any comments that had not been made previously in order to support their scores, and (iii) where relevant, re-select the appropriate BMI cut-off. During this round, members were also asked to suggest how each of the automatically included standards could be audited. Responses to the third iteration were analysed using the same methodology as for the second iteration. The distribution of scores and members’ anonymised comments were fed back to the group. 3.4.4. Agreement of standards All members were invited to attend a second meeting. Standards that had not met either the inclusion or exclusion criteria were reviewed at the meeting and consensus reached for each one. Following this, a list of the final agreed standards was sent to the CSG and members were given the opportunity to suggest essential re-wording to improve the clarity of the standards without influencing the content. This feedback was reviewed by the project researcher and senior clinician and final revisions made. 3.4.5. Levels of evidence Once the standards had been finalised, levels of evidence were assigned to each standard based on the supporting evidence submitted by the CSG during the consensus process. The levels and grades of evidence were derived using the methodology employed by the Scottish Intercollegiate Guidelines Network (2008); this grading system is also used by the RCOG for the development of their guidelines. CSG members were invited to review and comment on the provisional levels and grades of evidence via an online questionnaire. Members logging any disagreement were prompted to recommend a revised level and/or grade of evidence, together with references supporting the revision(s). All responses were reviewed, and the assigned levels and grades were revised in light of any new supporting evidence. Any changes to the levels of evidence were reviewed and approved by the project’s External Advisory Group.
4. Results of the consensus process and final standards of care for women with obesity All members of the group attended the first meeting and participated fully in the first three phases of the consensus process. Three members were not able to attend the second meeting and were therefore unable to participate during the final agreement of standards. The disciplines of those members not attending the second meeting were represented by other members who were present during the final agreement. Only three standards were scored by fewer than five members during phases 2 and 3. These standards remained in the process and were discussed during the second meeting. The total number of standards and the number meeting the consensus inclusion and exclusion criteria during each phase of the consensus process is described in Table 1.
Table 1 Number of standards at each phase of the consensus process. Phase
Number of standards
Phase 1 Phase 2
498 standards suggested by CSG 189 standards circulated for scoring; 29 met inclusion criteria; none met exclusion criteria 160 standards circulated for scoring; 6 met inclusion criteria; 1 met exclusion criteria 153 standards discussed at meeting; 3 included; 150 excluded 38 standards agreed
Phase 3 Phase 4 Phase 5
104
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
Box 5. Final standards of maternity care for women with obesity and the associated grade of evidencea Pre-pregnancy care 1. Primary care services should ensure that all women of childbearing age have the opportunity to optimise their weight before pregnancy. Advice on weight and lifestyle should be given during family planning consultations, and weight, body mass index and waist circumference should be regularly monitored. [D] 2. Women of childbearing age with BMI 30 should receive information and advice about the risks of obesity during pregnancy and childbirth,2 and be supported to lose weight before conception.30,31 [D] 3. Women with BMI 30 wishing to become pregnant should be advised to take 5 mg folic acid supplementation daily, starting at least one month before conception and continuing during the first trimester of pregnancy.18,32,33 [B] Provision of antenatal care 4. Management of women with obesity in pregnancy should be integrated into all antenatal clinics, with clear policies and guidelines for care available. [D] Measuring weight, height and body mass index (BMI) 5. All pregnant women should have their weight and height measured using appropriate equipment, and their body mass index calculated at the antenatal booking visit. Measurements should be recorded in the handheld notes and electronic patient information system. [D] Information-giving during pregnancy 6. All pregnant women with a booking BMI 30 should be provided with accurate and accessible information about the risks associated with obesity in pregnancy and how they may be minimised.2 Women should be given the opportunity to discuss this information. [D] Local guidelines 7. All maternity units should have accessible multidisciplinary guidelines that are communicated to all individuals and organisations providing care to pregnant women with a booking BMI 30. These guidelines should include consideration of: Referral criteria Facilities and equipment Care in pregnancy Place of birth and care in labour Provision of anaesthetic services Management of obstetric emergencies Postnatal advice [D] Facilities and equipment 8. All maternity units should have a documented environmental risk assessment regarding the availability of facilities to care for pregnant women with a booking BMI 30. This risk assessment should address the following issues: Circulation space Accessibility including doorway widths and thresholds Safe working loads of equipment (up to 250 kg) and floors Appropriate theatre gowns
a See Appendix for grading system of evidence [Scottish Intercollegiate Guidelines Network (SIGN)].
Equipment storage Transportation Staffing levels Availability of, and procurement process for, specific equipment: o large blood pressure cuffs o sit-on weighing scale o large chairs without arms o large wheelchairs o ultrasound scan couches o ward and delivery beds o theatre trolleys o operating theatre tables o lifting and lateral transfer equipment [D]
9. Maternity units should have a central list of all facilities and equipment required to provide safe care to pregnant women with a booking BMI 30. The list should include details of safe working loads, product dimensions, where specific equipment is located and how to access it. [D] 10. Operating theatre staff should be alerted regarding any woman whose weight exceeds 120 kg and who is due to have an operative intervention in theatre. [D] Education of health professionals 11. All health professionals involved in the care of pregnant women should receive education about maternal nutrition and its impact on maternal, fetal and child health.34 [D] 12. All health professionals involved in maternity care should receive training in manual handling techniques and the use of specialist bariatric equipment which may be required for pregnant and postnatal women with obesity. [D] Risk assessment during pregnancy 13. Pregnant women with a booking BMI 40 should have an antenatal consultation with an obstetric anaesthetist, so that potential difficulties with venous access, regional or general anaesthesia can be identified. An anaesthetic management plan for labour and delivery should be discussed and documented in the medical records. [D] 14. Women with a booking BMI 40 should have a documented assessment in the third trimester of pregnancy by an appropriately qualified professional to determine manual handling requirements for childbirth and should consider tissue viability issues. [D] Thromboprophylaxis 15. Women with a booking BMI 30 should be assessed at their first antenatal visit and throughout pregnancy for the risk of thromboembolism.9,10,35 Antenatal and postdelivery thromboprophylaxis should be considered in accordance with the RCOG Clinical Green Top Guideline No. 37.36 [B] 16. Women with a booking BMI 30 requiring pharmacological thromboprophylaxis should be prescribed doses appropriate for maternal weight, in accordance with the RCOG Clinical Green Top Guideline No. 37.36 [D] Maternal surveillance and screening 17. An appropriate size of arm cuff should be used for blood pressure measurements taken at the booking visit and all subsequent antenatal consultations.37 The cuff size used should be documented in the medical records. [C] 18. All pregnant women with a booking BMI 30 should be screened for gestational diabetes,7,19,38,39,40 as recommended by the NICE Clinical Guideline No. 63 (Diabetes in Pregnancy, July 2008).41 [B] 19. Women with a booking BMI 30 have an increased risk of and should have pre-eclampsia7,8,19,20,38,39,42,43,44
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
surveillance during pregnancy in accordance with the Preeclampsia Community Guideline (PRECOG), 2004.37 [B] Planning labour and delivery 20. Women with a booking BMI 30 should have an informed discussion antenatally about possible intrapartum complications associated with a high BMI,45 and management strategies considered. This should be documented in the notes. [D] 21. Women with a booking BMI 30 should have an individualised decision for VBAC (vaginal birth after caesarean) following informed discussion and consideration of all relevant clinical factors. [D] Care during childbirth 22. Women with a BMI 35 should give birth in a consultant-led obstetric unit with appropriate neonatal services,7,11,19,39 as recommended by the NICE Clinical Guideline No. 55 (Intrapartum Care, Sept 2007).46 [B] 23. In the absence of other obstetric or medical indications, obesity alone is not an indication for induction of labour and a normal birth should be encouraged. [D] 24. The duty anaesthetist covering labour ward should be informed when a woman with a BMI 40 is admitted to the labour ward if delivery or operative intervention is anticipated. This communication should be documented by the attending midwife in the notes. [D] 25. An obstetrician and an anaesthetist at Specialty Trainee year 6 and above, or with equivalent experience in a non-training post, should be informed and available for the care of women with a BMI 40 during labour and delivery, including attending any operative vaginal or abdominal delivery and physical review during the routine medical ward round. [D] 26. Women with BMI 40 should have venous access established early in labour. [D] 27. Women with BMI 40 who are in established labour should receive continuous midwifery care. [D] 28. All women with BMI 30 should be recommended to have active management of the third stage of labour.47 This should be documented in the notes. [B] 29. Women with BMI 30 having a caesarean section have an increased risk of wound infection,7,11,48 and should receive prophylactic antibiotics at the time of surgery as recommended by the NICE Clinical Guideline No. 13 (Caesarean Section, April 2004).49 [B] Care after childbirth 30. Women with BMI 30 should be encouraged to mobilise as early as practicable following childbirth to reduce the risk of thromboembolism.9 [B] 31. All women with BMI 40 should be offered postnatal thromboprophylaxis regardless of their mode of delivery. [D] 32. Obesity is associated with low breastfeeding initiation and maintenance rates.15,50 Women with a booking BMI 30 should receive appropriate specialist advice and support antenatally and postnatally regarding the benefits, initiation and maintenance of breastfeeding.51 [B] Follow-up after pregnancy 33. Women with a booking BMI 30 should continue to receive nutritional advice following childbirth from an appropriately trained professional, with a view to weight reduction.52,53 [C] 34. All women with a booking BMI 30 who have been diagnosed with gestational diabetes should have a test of glucose tolerance about 6 weeks after giving birth. [D] 35. Women with a booking BMI 30 and gestational diabetes who have a normal test of glucose tolerance
105
following childbirth, should have regular follow-up with the GP to screen for the development of type 2 diabetes.54 [B] 36. All women with a booking BMI 30 who have been diagnosed with gestational diabetes should have annual screening for cardio-metabolic risk factors, and be offered lifestyle and weight management advice.55 [B] Areas for further research 37. Research is needed to determine the optimal weight gain during pregnancy for women in different BMI categories. [D] 38. Evidence-based guidance is required on the optimal caesarean section technique for women with obesity in pregnancy. [D]
The final standards of maternity care for women with obesity are shown in Box 5. A total of 38 standards were agreed by the CSG, of which two are research recommendations. 5. Conclusions Maternal obesity significantly increases the risk of pregnancy complications and can pose a major challenge for health professionals providing maternity care. National clinical care guidelines have been developed by CMACE to minimise and manage the risks associated with maternal obesity. These guidelines were developed using formal consensus methods, and they are based on the best available evidence and the clinical experience of a large multidisciplinary group of experts in the area of maternal obesity. Although further research is required in some areas, there now appears to be sufficient evidence for maternity services to implement strategies to reduce the risks related to pregnancies in women with obesity. As part of the CEMACH programme, CMACE is carrying out a national (UK-wide) audit of care against the new maternity standards for obesity in pregnancy, and the findings of this audit will be published in 2010.
Practice points Women with BMI 30 wishing to become pregnant should be advised to take 5 mg folic acid supplementation daily, starting at least one month before conception and continuing during the first trimester of pregnancy. Maternal weight and height should be measured using appropriate equipment at the first antenatal appointment, and BMI should be calculated. An appropriate size of arm cuff should be used for blood pressure measurements. All pregnant women with a booking BMI 30 should be screened for gestational diabetes. Women with a booking BMI 40 should have a documented antenatal consultation with an obstetric anaesthetist. Women with a booking BMI 40 should have a documented assessment in the third trimester of pregnancy to determine manual handling requirements for childbirth and consider tissue viability issues. Women with BMI 40 should have venous access established early in labour. Women with BMI 30 should be recommended to have active management of the third stage of labour. All women with a BMI 40 should be offered postpartum thromboprophylaxis regardless of their mode of delivery.
106
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
References Research agenda The optimal weight gain during pregnancy for women in different BMI categories. The optimal caesarean section technique for women with obesity in pregnancy.
Acknowledgements This work was undertaken by the Centre for Maternal and Child Enquiries (CMACE) as part of the CEMACH programme. The work was funded by the National Patient Safety Agency; the Department of Health, Social Services and Public Safety of Northern Ireland; NHS Quality Improvement Scotland (QIS); and the Channel Islands and Isle of Man. We are grateful to the members of the CMACE Consensus Standards Group, who all contributed to the development of the obesity in pregnancy standards of care. The views expressed in this publication are those of CMACE and the Consensus Standards Group and not those of the funding bodies. Conflicts of interest None declared. Funding sources None. Appendix. Key to evidence statements and grades of recommendations: from SIGN 50: a guideline developer’s handbook. Guideline No. 50; ISBN 19781905813254. Levels of evidence 1þþ High quality meta-analyses, systematic reviews of randomised controlled trials (RCTs), or RCTs with a very low risk of bias 1þ Well-conducted meta-analyses, systematic reviews, or RCTs with a low risk of bias 1– Meta-analyses, systematic reviews, or RCTs with a high risk of bias 2þþ High quality systematic reviews of case–control or cohort or studies. High quality case control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal 2þ Well-conducted case–control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal 2– Case–control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal 3 Non-analytic studies, e.g. case reports, case series 4 Expert opinion
Grades of recommendations A At least one meta-analysis, systematic review, or RCT rated as 1þþ, and directly applicable to the target population; or A body of evidence consisting principally of studies rated as 1þ, directly applicable to the target population, and demonstrating overall consistency of results B A body of evidence including studies rated as 2þþ, directly applicable to the target population, and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 1þþ or 1þ C A body of evidence including studies rated as 2þ, directly applicable to the target population and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 2þþ D Evidence level 3 or 4; or Extrapolated evidence from studies rated as 2þ
1. World Health Organization. Obesity: preventing and managing the global epidemic. Geneva: World Health Organization; 2000. 2. Heslehurst N, Simpson H, Ells L, et al. The impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysis. Obes Rev 2008;9:635–83. 3. Heslehurst N, Ells LJ, Simpson H, et al. Trends in maternal obesity incidence rates, demographic predictors, and health inequalities in 36,821 women over a 15-year period. Br J Obstet Gynaecol 2007;114:187–94. 4. Kanagalingam MG, Forouhi NG, Greer IA, et al. Changes in booking body mass index over a decade: retrospective analysis from a Glasgow maternity hospital. Br J Obstet Gynaecol 2005;112:1431–3. 5. Department of Health. The health survey for England, 2006. London: Stationery Office; 2008. 6. Lashen H, Fear K, Sturdee DW. Obesity is associated with increased risk of first trimester and recurrent miscarriage: matched case–control study. Hum Reprod 2004;19:1644–6. 7. Sebire NJ, Jolly M, Harris JP, et al. Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London. Int J Obes Relat Metab Disord 2001;25: 1175–82. 8. O’Brien TE, Ray JG, Chan W- S. Maternal body mass index and the risk of preeclampsia: a systematic overview. Epidemiology 2003;14:368–74. 9. Jacobsen AF, Skjeldestad FE, Sandset PM. Ante- and postnatal risk factors of venous thrombosis: a hospital-based case control study. J Thromb Haemost 2008;6:905–12. 10. Larsen TB, Sorensen HT, Gislum M, et al. Maternal smoking, obesity, and risk of venous thromboembolism during pregnancy and the puerperium: a population-based nested case–control study. Thromb Res 2007;120:505–9. 11. Usha Kiran TS, Hemmadi S, Bethel J, et al. Outcome of pregnancy in a woman with an increased body mass index. Br J Obstet Gynaecol 2005;112:768–72. 12. Chu SY, Kim SY, Schmid CH, et al. Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes Rev 2007;8:385–94. 13. Dresner M, Brocklesby J, Bamber J. Audit of the influence of body mass index on the performance of epidural analgesia in labour and the subsequent mode of delivery. Br J Obstet Gynaecol 2006;113:1178–81. 14. Saravanakumar K, Rao SG, Cooper GM. The challenges of obesity and obstetric anaesthesia. Curr Opin Obstet Gynecol 2006;18:631–5. 15. Amir LH, Donath S. A systematic review of maternal obesity and breastfeeding intention, initiation and duration. BMC Pregn Childbirth 2007;7:9. 16. Chu SY, Kim SY, Lau J, et al. Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol 2007;197:223–8. 17. Kristensen J, Vestergaard M, Wisborg K, et al. Pre-pregnancy weight and the risk of stillbirth and neonatal death. Br J Obstet Gynaecol 2005;112:403–8. 18. Rasmussen SA, Chu SY, Kim SY, et al. Maternal obesity and risk of neural tube defects: a metaanalysis. Am J Obstet Gynecol 2008;198:611–9. 19. Callaway LK, Prins JB, Chang AM, et al. The prevalence and impact of overweight and obesity in an Australian obstetric population. Med J Aust 2006;184: 56–9. 20. Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol 2004;103:219–24. 21. Shah A, Sands J, Kenny L. Maternal obesity and the risk of still birth and neonatal death. J Obstet Gynaecol 2006;26(Suppl 1):S19. 22. Boney CM, Verma A, Tucker R, et al. Metabolic syndrome in childhood: association with birth weight, maternal obesity, and gestational diabetes mellitus. Pediatrics 2005;115:e290–6. 23. Raine R, Sanderson C, Hutchings A, et al. An experimental study of determinants of group judgments in clinical guideline development. Lancet 2004; 364(9432):429–37. 24. Reid N. The Delphi technique: its contribution to the evaluation of professional practice. In: Ellis R, editor. Professional competence and quality assurance in the caring professions. New York: Chapman & Hall; 1988. p. 230–62. 25. Thangaratinam S, Redman CWE. The Delphi technique. The Obstetrician and Gynaecologist 2005;7:120–5. 26. Murphy MK, Black NA, Lamping DL, et al. Consensus development methods, and their use in clinical guideline development. Health Technol Assessm 1998; 2(3):1–88. 27. Scottish Intercollegiate Guidelines Network (SIGN). Obesity in Scotland. Integrating prevention with weight management. Edinburgh: SIGN; 1996. 28. Ministry of Health. Clinical practice guidelines: obesity. Singapore: Ministry of Health; 2004. 29. American College of Obstetricians and Gynecologists, Committee on Gynecologic Practice. ACOG Committee Opinion number 315, September 2005. Obesity in pregnancy. Obstet Gynecol 2005;106:671–5. 30. Glazer NL, Hendrickson AF, Schellenbaum GD, et al. Weight change and the risk of gestational diabetes in obese women. Epidemiology 2004;15:733–7. 31. Carmichael SL, Shaw GM, Schaffer DM, et al. Dieting behaviors and risk of neural tube defects. Am J Epidemiol 2003;158:1127–31. 32. MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group. Lancet 1991;338(8760):131–7. 33. Werler MM, Louik C, Shapiro S, et al. Prepregnant weight in relation to risk of neural tube defects. J Am Med Assoc 1996;275:1089–92.
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107 34. Laraia BA, Bodnar LM, Siega-Riz AM. Pregravid body mass index is negatively associated with diet quality during pregnancy. Public Health Nutr 2007;10:920–6. 35. Knight M, on behalf of UKOSS. Antenatal pulmonary embolism: risk factors, management and outcomes. Br J Obstet Gynaecol 2008;115:453–61. 36. Royal College of Obstetricians and Gynaecologists. Green-Top Guideline No. 37. Thromboprophylaxis during pregnancy, labour and after vaginal delivery. London: RCOG; 2004. 37. Pre-eclampsia Community Guideline Development Group. Pre-eclampsia community guideline (PRECOG). Middlesex: Action on Pre-Eclampsia (APEC); 2004. 38. Bhattacharya S, Campbell DM, Liston WA, et al. Effect of body mass index on pregnancy outcomes in nulliparous women delivering singleton babies. BMC Publ Health 2007;7:168. 39. Bianco AT, Smilen SW, Davis Y, et al. Pregnancy outcome and weight gain recommendations for the morbidly obese woman. Obstet Gynecol 1998;91:60–4. 40. Crowther CA, Hiller JE, Moss JR, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med 2005;352:2477–86. 41. National Institute for Health and Clinical Excellence (NICE). Diabetes in pregnancy: Management of diabetes and its complications from pre-conception to the postnatal period. London: NICE; 2008. 42. Duckitt K, Harrington D. Risk factors for pre-eclampsia at antenatal booking: systematic review of controlled studies. Br Med J 2005;330(7491):549–50. 43. Sattar N, Clark P, Holmes ANN, et al. Antenatal waist circumference and hypertension risk. Obstet Gynecol 2001;97:268–71. 44. Weiss JL, Malone FD, Emig D, et al. Obesity, obstetric complications and cesarean delivery rate – a population-based screening study. Am J Obstet Gynecol 2004;190:1091–7. 45. Nuthalapaty FS, Rouse DJ, Owen J. The association of maternal weight with cesarean risk, labor duration, and cervical dilation rate during labor induction.
46. 47.
48.
49. 50.
51.
52.
53. 54. 55.
107
Obstet Gynecol 2004;103:452–6 [Published erratum in Obstet Gynecol 2004 May; 103(5 Pt 1): 1019.]. National Institute for Health and Clinical Excellence (NICE). Intrapartum care: care of healthy women and their babies during childbirth. London: NICE; 2007. Prendiville WJ, Elbourne D, McDonald S. Active versus expectant management in the third stage of labour. Cochrane Database Syst Rev 2000;(3) [Update of Cochrane Database Syst Rev 2000;(2):CD000007.]. Myles TD, Gooch J, Santolaya J. Obesity as an independent risk factor for infectious morbidity in patients who undergo cesarean delivery. Obstet Gynecol 2002;100(5 Pt 1):959–64. National Institute for Health and Clinical Excellence. Caesarean section. London: Royal College of Obstetricians and Gynaecologists; 2004. Mok E, Multon C, Piguel L, et al. Decreased full breastfeeding, altered practices, perceptions, and infant weight change of prepregnant obese women: a need for extra support. Pediatrics 2008;121:e1319–24. National Institute for Health and Clinical Excellence. Antenatal care: routine care for the healthy pregnant woman. London: Royal College of Obstetricians and Gynaecologists; 2008. Leermakers EA, Anglin K, Wing RR. Reducing postpartum weight retention through a correspondence intervention. Int J Obes Relat Metab Disord 1998;22: 1103–9. O’Toole ML, Sawicki MA, Artal R. Structured diet and physical activity prevent postpartum weight retention. J Women’s Health (Larchmt) 2003;12:991–8. Kim C, Newton KM, Knopp RH. Gestational diabetes and the incidence of type 2 diabetes: a systematic review. Diabetes Care 2002;25:1862–8. Orozco LJ, Buchleitner AM, Gimenez-Perez G, et al. Exercise or exercise and diet for preventing type 2 diabetes mellitus. Cochrane Database Syst Rev 2008;(3). CD003054.
Contents lists available at ScienceDirect
Seminars in Fetal & Neonatal Medicine journal homepage: www.elsevier.com/locate/siny
Setting maternity care standards for women with obesity in pregnancy Kate J. Fitzsimons a, *, J. Modder a, b a b
Centre for Maternal and Child Enquiries, Chiltern Court, 188 Baker Street, London NW1 5SD, UK UCLH NHS Foundation Trust, 250 Euston Road, London NW1 2PG, UK
s u m m a r y Keywords: Body mass index Guideline Management Obesity Pregnancy
Obesity is associated with an increased risk of pregnancy-related complications that affect both the mother and baby. National clinical care guidelines have been developed by the Centre for Maternal and Child Enquiries, as part of its Confidential Enquiry into Maternal and Child Health (CEMACH) programme. These guidelines are intended to minimise and manage the risks associated with maternal obesity, and they were developed using formal consensus methods based on the Delphi technique. A multidisciplinary group of 25 members participated in the iterative process. Standards of care were based on the best available evidence and expert clinical knowledge and experience. This article describes the process used to develop standards of maternity care for women with obesity, and the resulting recommendations are presented. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction The worldwide prevalence of obesity has increased markedly over the past few decades, with the World Health Organization describing this trend as a ‘global epidemic’ posing a serious threat to public health.1 The increasing prevalence of obesity among women of childbearing age is of particular concern as obesity in pregnancy carries significant additional risks for both mother and baby.2 Obesity in pregnancy is widely defined as a maternal body mass index (BMI; kg/m2) of 30 at the time of the first antenatal consultation. At present, no national-level data on the prevalence of obesity in pregnancy are available in the UK. In 2002–2004, two observational studies reported maternal obesity prevalence rates of 16% and 18% respectively in the North East region of England3 and at a maternity unit in Glasgow;4 however, the prevalence of obesity in the general population has continued to increase since that time,5 which presupposes an increasing prevalence in the general maternity population also. Maternal obesity is now considered one of the most commonly occurring risk factors in obstetric practice, and obstetricians and midwives are increasingly faced with caring for women who are obese. Compared to women with a healthy prepregnancy weight, pregnant women with obesity are at increased risk of miscarriage,6 gestational diabetes,7 pre-eclampsia,8 venous thromboembolism,9,10 induced labour,11 caesarean section,12 anaesthetic complications13,14
* Corresponding author. Tel.: þ44 207 467 3231; fax: þ44 207 486 6543. E-mail address: [email protected] (K.J. Fitzsimons). 1744-165X/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.siny.2009.09.004
and wound infections,7 and they are less likely to initiate or maintain breastfeeding.15 Babies of obese mothers are at significantly increased risk of stillbirth,16,17 congenital anomalies,18 prematurity,19 macrosomia7,11,20 and neonatal death.17,20,21 Intrauterine exposure to maternal obesity is also associated with an increased risk of developing obesity and metabolic disorders in childhood.22 It is clear that women with obesity pose particular management problems relating both to the increased risks of specific complications in pregnancy, as well as the medical, surgical and technical challenges in providing safe maternity care. Despite these welldocumented problems, there is currently no national clinical guideline available in the UK with regard to the clinical care and provision of services for women with obesity in pregnancy. In 2008, the Confidential Enquiry into Maternal and Child Health (CEMACH), now known as the Centre for Maternal and Child Enquires (CMACE) commenced a three-year national Obesity in Pregnancy project as part of its CEMACH programme. This project was initiated in response to a number of factors, including: (i) growing evidence that obesity is clearly associated with increased morbidity and mortality for both mother and baby, (ii) unknown national and regional prevalence rates, and (iii) the absence of a national clinical guideline available in the UK. The project comprises three phases, as shown in Box 1. One of the key objectives of the CMACE project was to develop recommendations to guide clinical care aimed at minimising complications in this high risk group of women, and ultimately help to improve pregnancy outcomes. While clinical recommendations should be derived from the highest level of research evidence available, it is recognised that in practice there may be particular areas where there is a dearth of evidence on which to formulate
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
Box 1. Phases of the Centre for Maternal and Child Enquiries (CMACE) Obesity in Pregnancy Project Phase 1 A national survey investigating how well maternity units are equipped to care for women with obesity Phase 2 The development of national standards of care based on evidence and consensus expert opinion Phase 3 A national audit of care provided to women with body mass index 35
recommendations. In these circumstances, it is necessary to develop recommendations based on a robust process gathering together expert opinion and experience. Formal consensus methods offer a means of synthesising and collating a number of individual judgements. Such techniques are increasingly being employed in the development of guidelines in the health sector, in situations where there is a relatively limited evidence-base for practice.23 One of the most commonly used formal consensus methods is the Delphi method (also sometimes known as the Delphi technique), which offers a way of systematically collecting and aggregating informed judgements from a group of experts on a specific topic24 and is particularly suitable for developing clinical guidelines when there is limited research evidence.25,26 Key features of the method include: (i) the use of expert opinion, (ii) a number of iterative questionnaire ‘rounds’ in which members score items, (iii) the quantitative analysis of scores which is fed back to the group, together with any qualitative comments that accompanied the scores, (iv) the opportunity for group members to modify their responses in light of the group feedback from the previous round, and (v) the anonymity of the experts’ responses from each other. One of the main advantages of the Delphi method is that the process can be performed without the need for repeated physical meetings by group members. The CMACE obesity in pregnancy project utilised a modified Delphi approach to develop standards of maternity care for women with obesity, and the specific methodology and resulting final standards are described in this article. 2. Standards of maternity care for obesity in pregnancy outside of the UK A search was carried out to identify guidelines published by recognised professional organisations for the management of obesity in pregnancy. There is currently limited guidance on the range of issues associated with maternal obesity. The Scottish Intercollegiate Guidelines Network (SIGN) Guideline No. 8 (1996) on Obesity recommended that weight loss should be avoided around the time of conception and during pregnancy, although it also stated that limiting weight gain to 6 kg instead of the more usual 12 kg may be advisable in order to avoid co-morbidities such as gestational diabetes and pre-eclampsia.27 The Clinical Practice Guideline on Obesity published jointly in 2004 by the Singapore Ministry of Health and Singapore Association for the Study of Obesity recommended that bariatric surgery should not be performed during pregnancy, that women of childbearing age should practice secure contraception during the period of rapid weight loss following bariatric surgery, and that adjustable gastric bands should be deflated during pregnancy to allow for ‘normal weight gain’.28 The most detailed guidance to date was published in an American College of Obstetricians and Gynaecologists Committee Opinion paper in September 2005. This paper reviewed the evidence for adverse outcomes in pregnancy, such as pre-eclampsia, gestational diabetes, a high caesarean section rate and difficult anaesthesia, and made a number
101
of recommendations, including the need to record maternal height and weight at the first prenatal visit, encouraging an exercise programme during pregnancy, screening for gestational diabetes, the importance of antenatal anaesthetic review, and consideration of surgical techniques to minimise operative complications.29 3. Methodology for developing standards of maternity care for women with obesity in pregnancy in the UK The methodology used by CMACE to develop standards of care included searching for and preparing scientific evidence, consulting with stakeholders, establishing an expert multidisciplinary group, and facilitating the development of standards of maternity care through a formal consensus process. 3.1. Preparation of scientific evidence A review of the literature was performed electronically through Medline, Embase and the Cochrane Database of Systematic Reviews. Search terms relating to obesity, pregnancy, services and interventions were restricted to the titles of English language articles that were related to humans, and had been published in the previous 10 years. Articles were selected if they: (i) related to general care issues for pregnant obese women, (ii) focused on the management of obesity or obesity-related complications in pregnancy, or (iii) focused on the relationship between maternal BMI and pregnancyrelated outcomes. A list of articles meeting the selection criteria was reviewed by the CMACE Obesity Project’s External Advisory Group (a multidisciplinary group of nine senior health professionals with expertise in pregnancy and obesity). Any additional references recommended by the external advisory group were located and assessed according to the criteria above. All articles that met the selection criteria were organised into categories. Tables of evidence were created from the articles which described the type of study and key findings. Each article identified by the initial search criteria was examined to assess its suitability for inclusion in the evidence tables. Box 2 shows the inclusion and exclusion criteria that were used to assess each article.
Box 2. Article inclusion and exclusion criteria for tables of evidence Inclusion criteria Meta-analyses Intervention studies (including randomised controlled trials, randomised trials and controlled trials) Observational studies (including prospective, retrospective, cross-sectional) Cross-sectional surveys Systematic reviews Exclusion criteria Narrative reviews (excepting anaesthesia) Case reports Comments/letters
3.2. Stakeholder consultation Organisations representing healthcare professionals, researchers or patients with an interest in the area of obesity in pregnancy were invited to participate in a consultation exercise. A total of 44 stakeholder organisations were invited to suggest aspects of care or service provision that should be covered by the consensus
102
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
standards. Twelve stakeholder organisations responded during the four-week consultation period. After collating and aggregating the responses, a total of 30 broad areas of care were identified and subsequently presented to the Consensus Standards Group (see below) for consideration.
Consensus Standards Group (CSG) convened
Stakeholder consultation
Literature review and tabulation of evidence
Tabulated evidence sent to CSG
3.3. Establishing a multidisciplinary consensus standards group First CSG meeting
A multidisciplinary group of experts (Consensus Standards Group, CSG) was convened. The group consisted of 25 members who represented a range of disciplines relevant to obesity and pregnancy (see Box 3). The group included two lay representatives with personal experience of obesity and pregnancy. Of the 25 members, six were nominated by UK Royal Colleges representing major professional stakeholders: the Royal College of Anaesthetists (RCA), the Royal College of General Practitioners (RCGP), the Royal College of Midwives (RCM), the Royal College of Obstetricians and Gynaecologists (RCOG), the Royal College of Physicians (RCP) and the Royal College of Paediatrics and Child Health (RCPCH).
Questionnaire developed around agreed areas for standards
Phase 1
Open-ended questionnaire (1) circulated to CSG for suggested standards of care
Responses categorised into common themes and used to construct a series of statements
List of statements [questionnaire (2)] circulated to CSG for feedback on wording
Statements edited according to feedback
Box 3. Disciplines represented by the multidisciplinary group responsible for developing national standards of maternity care for women with obesity
Revised questionnaire (2) circulated to CSG for members to score each Phase 2
standard on a scale of 1–5 for importance and feasibility, and provide comments to justify score
Anaesthesia Dietetics Endocrinology General practice General medicine Manual handling Midwifery Neonatology Obstetrics Physiotherapy Public health Ultrasonography
Individual scores and comments collated, anonymised and added to questionnaire.
Phase 3
Questionnaire (2) with collated scores and anonymised comments circulated to CSG for members to re-score standards where consensus was not reached
Final scores analysed to determine standards where consensus was reached for inclusion or exclusion
Phase 4
3.4. Consensus process
Second meeting to discuss and achieve consensus on outstanding standards
Final consensus standards drawn up
Tables of evidence and the proposed process for developing standards were sent to all CSG members in advance of the first meeting. During the meeting, the group was required to agree: (i) the broad areas for the standards, (ii) the iteration process for achieving consensus, and (iii) the scoring system to include or exclude standards. The process of developing the standards using a modified Delphi approach is illustrated in Fig. 1.
Final standards circulated to CSG for members to suggest any re-wording of standards
Final standards edited according to feedback
Levels and grades of evidence assigned based on the research evidence cited by the CSG in support of each standard
3.4.1. First iteration Shortly after the first meeting, an electronic open-ended questionnaire was emailed to the CSG. Members were asked to submit draft standards within their area of expertise, together with the rationale for the standard and citations of the supporting evidence. A total of 498 standards were suggested by the group. All suggested standards were analysed qualitatively by a researcher and senior clinician based at CMACE. This analysis involved sorting and categorising the proposed standards according to common themes. Many suggested standards overlapped significantly, and once duplicates had been removed there were a total of 198 possible standards. These were then edited in-house by CMACE. The CSG was given the opportunity to suggest any essential rewording prior to the second iteration.
Edited standards and provisional levels and grades of evidence circulated to Phase 5
CSG, for logging of agreement/disagreement and suggestion of alternative levels and grades if necessary
Responses collated and levels and grades of evidence revised as appropriate based on the best available evidence
Final standards reviewed by Obesity Project External Advisory Group Fig. 1. Process for developing the standards of maternity care for women with obesity: the modified Delphi method.
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
3.4.2. Second iteration The second questionnaire sent to the Consensus Standards Group included each of the 198 suggested standards from Round 1 as well as members’ supporting rationales and references. Group members were requested to: (i) score each standard on importance and feasibility, (ii) provide the rationale for their scores, (iii) consider auditability of the standard, and (iv) consider the most appropriate BMI cut-off for specific standards. Importance and feasibility scoring was on a 5-point scale (Box 4). Members had the option of not scoring if they considered that they lacked sufficient knowledge of the area.
Box 4. The 5-point scale used for scoring standards on importance and feasibility Importance scale 1. Not at all important 2. Slightly important 3. Moderately important 4. Very important 5. Extremely important X. Unable to score due to insufficient knowledge Feasibility scale 1. Not at all feasible 2. Slightly feasible 3. Moderately feasible 4. Very feasible 5. Extremely feasible X. Unable to score due to insufficient knowledge
Members of the group were asked to score standards for importance based on their potential clinical impact and the level of available evidence. Scores for feasibility were given according to the likelihood of successful implementation of the standard. Responses to the second iteration were analysed quantitatively to determine whether consensus had been reached. Consensus was defined as 80% of responses occurring within two adjacent scores (e.g. 80% scoring 4 or 5). It was agreed by the group in advance that if 80% of members scored a standard highly (4 or 5), and there were no outliers (scores of 1 or 2), the standard would be automatically included. If 80% scored a standard poorly (1 or 2), and there were no outliers (scores of 4 or 5), the standard would be automatically excluded. Standards meeting the automatic inclusion or exclusion criteria at the end of the second iteration were removed from the subsequent scoring round. Standards not meeting the inclusion or exclusion criteria were rescored by members in the third iteration. A minimum of five members were required to score each standard. Standards without a minimum of five scores remained in the process, regardless of the distribution of scores. 3.4.3. Third iteration The third questionnaire sent to the CSG included bar charts showing the distribution of importance and feasibility scores from the second iteration. Comments made by members to support each importance score were anonymised and made available to the whole group. Individual scores were fed back to those who had submitted them so that members were able to review their own scores in comparison to all responses. A list of the standards meeting the inclusion and exclusion criteria was also provided. For those standards that did not meet the inclusion or exclusion criteria after the first scoring round, members were requested to:
103
(i) re-score each standard on importance and feasibility, (ii) provide any comments that had not been made previously in order to support their scores, and (iii) where relevant, re-select the appropriate BMI cut-off. During this round, members were also asked to suggest how each of the automatically included standards could be audited. Responses to the third iteration were analysed using the same methodology as for the second iteration. The distribution of scores and members’ anonymised comments were fed back to the group. 3.4.4. Agreement of standards All members were invited to attend a second meeting. Standards that had not met either the inclusion or exclusion criteria were reviewed at the meeting and consensus reached for each one. Following this, a list of the final agreed standards was sent to the CSG and members were given the opportunity to suggest essential re-wording to improve the clarity of the standards without influencing the content. This feedback was reviewed by the project researcher and senior clinician and final revisions made. 3.4.5. Levels of evidence Once the standards had been finalised, levels of evidence were assigned to each standard based on the supporting evidence submitted by the CSG during the consensus process. The levels and grades of evidence were derived using the methodology employed by the Scottish Intercollegiate Guidelines Network (2008); this grading system is also used by the RCOG for the development of their guidelines. CSG members were invited to review and comment on the provisional levels and grades of evidence via an online questionnaire. Members logging any disagreement were prompted to recommend a revised level and/or grade of evidence, together with references supporting the revision(s). All responses were reviewed, and the assigned levels and grades were revised in light of any new supporting evidence. Any changes to the levels of evidence were reviewed and approved by the project’s External Advisory Group.
4. Results of the consensus process and final standards of care for women with obesity All members of the group attended the first meeting and participated fully in the first three phases of the consensus process. Three members were not able to attend the second meeting and were therefore unable to participate during the final agreement of standards. The disciplines of those members not attending the second meeting were represented by other members who were present during the final agreement. Only three standards were scored by fewer than five members during phases 2 and 3. These standards remained in the process and were discussed during the second meeting. The total number of standards and the number meeting the consensus inclusion and exclusion criteria during each phase of the consensus process is described in Table 1.
Table 1 Number of standards at each phase of the consensus process. Phase
Number of standards
Phase 1 Phase 2
498 standards suggested by CSG 189 standards circulated for scoring; 29 met inclusion criteria; none met exclusion criteria 160 standards circulated for scoring; 6 met inclusion criteria; 1 met exclusion criteria 153 standards discussed at meeting; 3 included; 150 excluded 38 standards agreed
Phase 3 Phase 4 Phase 5
104
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
Box 5. Final standards of maternity care for women with obesity and the associated grade of evidencea Pre-pregnancy care 1. Primary care services should ensure that all women of childbearing age have the opportunity to optimise their weight before pregnancy. Advice on weight and lifestyle should be given during family planning consultations, and weight, body mass index and waist circumference should be regularly monitored. [D] 2. Women of childbearing age with BMI 30 should receive information and advice about the risks of obesity during pregnancy and childbirth,2 and be supported to lose weight before conception.30,31 [D] 3. Women with BMI 30 wishing to become pregnant should be advised to take 5 mg folic acid supplementation daily, starting at least one month before conception and continuing during the first trimester of pregnancy.18,32,33 [B] Provision of antenatal care 4. Management of women with obesity in pregnancy should be integrated into all antenatal clinics, with clear policies and guidelines for care available. [D] Measuring weight, height and body mass index (BMI) 5. All pregnant women should have their weight and height measured using appropriate equipment, and their body mass index calculated at the antenatal booking visit. Measurements should be recorded in the handheld notes and electronic patient information system. [D] Information-giving during pregnancy 6. All pregnant women with a booking BMI 30 should be provided with accurate and accessible information about the risks associated with obesity in pregnancy and how they may be minimised.2 Women should be given the opportunity to discuss this information. [D] Local guidelines 7. All maternity units should have accessible multidisciplinary guidelines that are communicated to all individuals and organisations providing care to pregnant women with a booking BMI 30. These guidelines should include consideration of: Referral criteria Facilities and equipment Care in pregnancy Place of birth and care in labour Provision of anaesthetic services Management of obstetric emergencies Postnatal advice [D] Facilities and equipment 8. All maternity units should have a documented environmental risk assessment regarding the availability of facilities to care for pregnant women with a booking BMI 30. This risk assessment should address the following issues: Circulation space Accessibility including doorway widths and thresholds Safe working loads of equipment (up to 250 kg) and floors Appropriate theatre gowns
a See Appendix for grading system of evidence [Scottish Intercollegiate Guidelines Network (SIGN)].
Equipment storage Transportation Staffing levels Availability of, and procurement process for, specific equipment: o large blood pressure cuffs o sit-on weighing scale o large chairs without arms o large wheelchairs o ultrasound scan couches o ward and delivery beds o theatre trolleys o operating theatre tables o lifting and lateral transfer equipment [D]
9. Maternity units should have a central list of all facilities and equipment required to provide safe care to pregnant women with a booking BMI 30. The list should include details of safe working loads, product dimensions, where specific equipment is located and how to access it. [D] 10. Operating theatre staff should be alerted regarding any woman whose weight exceeds 120 kg and who is due to have an operative intervention in theatre. [D] Education of health professionals 11. All health professionals involved in the care of pregnant women should receive education about maternal nutrition and its impact on maternal, fetal and child health.34 [D] 12. All health professionals involved in maternity care should receive training in manual handling techniques and the use of specialist bariatric equipment which may be required for pregnant and postnatal women with obesity. [D] Risk assessment during pregnancy 13. Pregnant women with a booking BMI 40 should have an antenatal consultation with an obstetric anaesthetist, so that potential difficulties with venous access, regional or general anaesthesia can be identified. An anaesthetic management plan for labour and delivery should be discussed and documented in the medical records. [D] 14. Women with a booking BMI 40 should have a documented assessment in the third trimester of pregnancy by an appropriately qualified professional to determine manual handling requirements for childbirth and should consider tissue viability issues. [D] Thromboprophylaxis 15. Women with a booking BMI 30 should be assessed at their first antenatal visit and throughout pregnancy for the risk of thromboembolism.9,10,35 Antenatal and postdelivery thromboprophylaxis should be considered in accordance with the RCOG Clinical Green Top Guideline No. 37.36 [B] 16. Women with a booking BMI 30 requiring pharmacological thromboprophylaxis should be prescribed doses appropriate for maternal weight, in accordance with the RCOG Clinical Green Top Guideline No. 37.36 [D] Maternal surveillance and screening 17. An appropriate size of arm cuff should be used for blood pressure measurements taken at the booking visit and all subsequent antenatal consultations.37 The cuff size used should be documented in the medical records. [C] 18. All pregnant women with a booking BMI 30 should be screened for gestational diabetes,7,19,38,39,40 as recommended by the NICE Clinical Guideline No. 63 (Diabetes in Pregnancy, July 2008).41 [B] 19. Women with a booking BMI 30 have an increased risk of and should have pre-eclampsia7,8,19,20,38,39,42,43,44
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
surveillance during pregnancy in accordance with the Preeclampsia Community Guideline (PRECOG), 2004.37 [B] Planning labour and delivery 20. Women with a booking BMI 30 should have an informed discussion antenatally about possible intrapartum complications associated with a high BMI,45 and management strategies considered. This should be documented in the notes. [D] 21. Women with a booking BMI 30 should have an individualised decision for VBAC (vaginal birth after caesarean) following informed discussion and consideration of all relevant clinical factors. [D] Care during childbirth 22. Women with a BMI 35 should give birth in a consultant-led obstetric unit with appropriate neonatal services,7,11,19,39 as recommended by the NICE Clinical Guideline No. 55 (Intrapartum Care, Sept 2007).46 [B] 23. In the absence of other obstetric or medical indications, obesity alone is not an indication for induction of labour and a normal birth should be encouraged. [D] 24. The duty anaesthetist covering labour ward should be informed when a woman with a BMI 40 is admitted to the labour ward if delivery or operative intervention is anticipated. This communication should be documented by the attending midwife in the notes. [D] 25. An obstetrician and an anaesthetist at Specialty Trainee year 6 and above, or with equivalent experience in a non-training post, should be informed and available for the care of women with a BMI 40 during labour and delivery, including attending any operative vaginal or abdominal delivery and physical review during the routine medical ward round. [D] 26. Women with BMI 40 should have venous access established early in labour. [D] 27. Women with BMI 40 who are in established labour should receive continuous midwifery care. [D] 28. All women with BMI 30 should be recommended to have active management of the third stage of labour.47 This should be documented in the notes. [B] 29. Women with BMI 30 having a caesarean section have an increased risk of wound infection,7,11,48 and should receive prophylactic antibiotics at the time of surgery as recommended by the NICE Clinical Guideline No. 13 (Caesarean Section, April 2004).49 [B] Care after childbirth 30. Women with BMI 30 should be encouraged to mobilise as early as practicable following childbirth to reduce the risk of thromboembolism.9 [B] 31. All women with BMI 40 should be offered postnatal thromboprophylaxis regardless of their mode of delivery. [D] 32. Obesity is associated with low breastfeeding initiation and maintenance rates.15,50 Women with a booking BMI 30 should receive appropriate specialist advice and support antenatally and postnatally regarding the benefits, initiation and maintenance of breastfeeding.51 [B] Follow-up after pregnancy 33. Women with a booking BMI 30 should continue to receive nutritional advice following childbirth from an appropriately trained professional, with a view to weight reduction.52,53 [C] 34. All women with a booking BMI 30 who have been diagnosed with gestational diabetes should have a test of glucose tolerance about 6 weeks after giving birth. [D] 35. Women with a booking BMI 30 and gestational diabetes who have a normal test of glucose tolerance
105
following childbirth, should have regular follow-up with the GP to screen for the development of type 2 diabetes.54 [B] 36. All women with a booking BMI 30 who have been diagnosed with gestational diabetes should have annual screening for cardio-metabolic risk factors, and be offered lifestyle and weight management advice.55 [B] Areas for further research 37. Research is needed to determine the optimal weight gain during pregnancy for women in different BMI categories. [D] 38. Evidence-based guidance is required on the optimal caesarean section technique for women with obesity in pregnancy. [D]
The final standards of maternity care for women with obesity are shown in Box 5. A total of 38 standards were agreed by the CSG, of which two are research recommendations. 5. Conclusions Maternal obesity significantly increases the risk of pregnancy complications and can pose a major challenge for health professionals providing maternity care. National clinical care guidelines have been developed by CMACE to minimise and manage the risks associated with maternal obesity. These guidelines were developed using formal consensus methods, and they are based on the best available evidence and the clinical experience of a large multidisciplinary group of experts in the area of maternal obesity. Although further research is required in some areas, there now appears to be sufficient evidence for maternity services to implement strategies to reduce the risks related to pregnancies in women with obesity. As part of the CEMACH programme, CMACE is carrying out a national (UK-wide) audit of care against the new maternity standards for obesity in pregnancy, and the findings of this audit will be published in 2010.
Practice points Women with BMI 30 wishing to become pregnant should be advised to take 5 mg folic acid supplementation daily, starting at least one month before conception and continuing during the first trimester of pregnancy. Maternal weight and height should be measured using appropriate equipment at the first antenatal appointment, and BMI should be calculated. An appropriate size of arm cuff should be used for blood pressure measurements. All pregnant women with a booking BMI 30 should be screened for gestational diabetes. Women with a booking BMI 40 should have a documented antenatal consultation with an obstetric anaesthetist. Women with a booking BMI 40 should have a documented assessment in the third trimester of pregnancy to determine manual handling requirements for childbirth and consider tissue viability issues. Women with BMI 40 should have venous access established early in labour. Women with BMI 30 should be recommended to have active management of the third stage of labour. All women with a BMI 40 should be offered postpartum thromboprophylaxis regardless of their mode of delivery.
106
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107
References Research agenda The optimal weight gain during pregnancy for women in different BMI categories. The optimal caesarean section technique for women with obesity in pregnancy.
Acknowledgements This work was undertaken by the Centre for Maternal and Child Enquiries (CMACE) as part of the CEMACH programme. The work was funded by the National Patient Safety Agency; the Department of Health, Social Services and Public Safety of Northern Ireland; NHS Quality Improvement Scotland (QIS); and the Channel Islands and Isle of Man. We are grateful to the members of the CMACE Consensus Standards Group, who all contributed to the development of the obesity in pregnancy standards of care. The views expressed in this publication are those of CMACE and the Consensus Standards Group and not those of the funding bodies. Conflicts of interest None declared. Funding sources None. Appendix. Key to evidence statements and grades of recommendations: from SIGN 50: a guideline developer’s handbook. Guideline No. 50; ISBN 19781905813254. Levels of evidence 1þþ High quality meta-analyses, systematic reviews of randomised controlled trials (RCTs), or RCTs with a very low risk of bias 1þ Well-conducted meta-analyses, systematic reviews, or RCTs with a low risk of bias 1– Meta-analyses, systematic reviews, or RCTs with a high risk of bias 2þþ High quality systematic reviews of case–control or cohort or studies. High quality case control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal 2þ Well-conducted case–control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal 2– Case–control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal 3 Non-analytic studies, e.g. case reports, case series 4 Expert opinion
Grades of recommendations A At least one meta-analysis, systematic review, or RCT rated as 1þþ, and directly applicable to the target population; or A body of evidence consisting principally of studies rated as 1þ, directly applicable to the target population, and demonstrating overall consistency of results B A body of evidence including studies rated as 2þþ, directly applicable to the target population, and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 1þþ or 1þ C A body of evidence including studies rated as 2þ, directly applicable to the target population and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 2þþ D Evidence level 3 or 4; or Extrapolated evidence from studies rated as 2þ
1. World Health Organization. Obesity: preventing and managing the global epidemic. Geneva: World Health Organization; 2000. 2. Heslehurst N, Simpson H, Ells L, et al. The impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysis. Obes Rev 2008;9:635–83. 3. Heslehurst N, Ells LJ, Simpson H, et al. Trends in maternal obesity incidence rates, demographic predictors, and health inequalities in 36,821 women over a 15-year period. Br J Obstet Gynaecol 2007;114:187–94. 4. Kanagalingam MG, Forouhi NG, Greer IA, et al. Changes in booking body mass index over a decade: retrospective analysis from a Glasgow maternity hospital. Br J Obstet Gynaecol 2005;112:1431–3. 5. Department of Health. The health survey for England, 2006. London: Stationery Office; 2008. 6. Lashen H, Fear K, Sturdee DW. Obesity is associated with increased risk of first trimester and recurrent miscarriage: matched case–control study. Hum Reprod 2004;19:1644–6. 7. Sebire NJ, Jolly M, Harris JP, et al. Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London. Int J Obes Relat Metab Disord 2001;25: 1175–82. 8. O’Brien TE, Ray JG, Chan W- S. Maternal body mass index and the risk of preeclampsia: a systematic overview. Epidemiology 2003;14:368–74. 9. Jacobsen AF, Skjeldestad FE, Sandset PM. Ante- and postnatal risk factors of venous thrombosis: a hospital-based case control study. J Thromb Haemost 2008;6:905–12. 10. Larsen TB, Sorensen HT, Gislum M, et al. Maternal smoking, obesity, and risk of venous thromboembolism during pregnancy and the puerperium: a population-based nested case–control study. Thromb Res 2007;120:505–9. 11. Usha Kiran TS, Hemmadi S, Bethel J, et al. Outcome of pregnancy in a woman with an increased body mass index. Br J Obstet Gynaecol 2005;112:768–72. 12. Chu SY, Kim SY, Schmid CH, et al. Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes Rev 2007;8:385–94. 13. Dresner M, Brocklesby J, Bamber J. Audit of the influence of body mass index on the performance of epidural analgesia in labour and the subsequent mode of delivery. Br J Obstet Gynaecol 2006;113:1178–81. 14. Saravanakumar K, Rao SG, Cooper GM. The challenges of obesity and obstetric anaesthesia. Curr Opin Obstet Gynecol 2006;18:631–5. 15. Amir LH, Donath S. A systematic review of maternal obesity and breastfeeding intention, initiation and duration. BMC Pregn Childbirth 2007;7:9. 16. Chu SY, Kim SY, Lau J, et al. Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol 2007;197:223–8. 17. Kristensen J, Vestergaard M, Wisborg K, et al. Pre-pregnancy weight and the risk of stillbirth and neonatal death. Br J Obstet Gynaecol 2005;112:403–8. 18. Rasmussen SA, Chu SY, Kim SY, et al. Maternal obesity and risk of neural tube defects: a metaanalysis. Am J Obstet Gynecol 2008;198:611–9. 19. Callaway LK, Prins JB, Chang AM, et al. The prevalence and impact of overweight and obesity in an Australian obstetric population. Med J Aust 2006;184: 56–9. 20. Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol 2004;103:219–24. 21. Shah A, Sands J, Kenny L. Maternal obesity and the risk of still birth and neonatal death. J Obstet Gynaecol 2006;26(Suppl 1):S19. 22. Boney CM, Verma A, Tucker R, et al. Metabolic syndrome in childhood: association with birth weight, maternal obesity, and gestational diabetes mellitus. Pediatrics 2005;115:e290–6. 23. Raine R, Sanderson C, Hutchings A, et al. An experimental study of determinants of group judgments in clinical guideline development. Lancet 2004; 364(9432):429–37. 24. Reid N. The Delphi technique: its contribution to the evaluation of professional practice. In: Ellis R, editor. Professional competence and quality assurance in the caring professions. New York: Chapman & Hall; 1988. p. 230–62. 25. Thangaratinam S, Redman CWE. The Delphi technique. The Obstetrician and Gynaecologist 2005;7:120–5. 26. Murphy MK, Black NA, Lamping DL, et al. Consensus development methods, and their use in clinical guideline development. Health Technol Assessm 1998; 2(3):1–88. 27. Scottish Intercollegiate Guidelines Network (SIGN). Obesity in Scotland. Integrating prevention with weight management. Edinburgh: SIGN; 1996. 28. Ministry of Health. Clinical practice guidelines: obesity. Singapore: Ministry of Health; 2004. 29. American College of Obstetricians and Gynecologists, Committee on Gynecologic Practice. ACOG Committee Opinion number 315, September 2005. Obesity in pregnancy. Obstet Gynecol 2005;106:671–5. 30. Glazer NL, Hendrickson AF, Schellenbaum GD, et al. Weight change and the risk of gestational diabetes in obese women. Epidemiology 2004;15:733–7. 31. Carmichael SL, Shaw GM, Schaffer DM, et al. Dieting behaviors and risk of neural tube defects. Am J Epidemiol 2003;158:1127–31. 32. MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group. Lancet 1991;338(8760):131–7. 33. Werler MM, Louik C, Shapiro S, et al. Prepregnant weight in relation to risk of neural tube defects. J Am Med Assoc 1996;275:1089–92.
K.J. Fitzsimons, J. Modder / Seminars in Fetal & Neonatal Medicine 15 (2010) 100–107 34. Laraia BA, Bodnar LM, Siega-Riz AM. Pregravid body mass index is negatively associated with diet quality during pregnancy. Public Health Nutr 2007;10:920–6. 35. Knight M, on behalf of UKOSS. Antenatal pulmonary embolism: risk factors, management and outcomes. Br J Obstet Gynaecol 2008;115:453–61. 36. Royal College of Obstetricians and Gynaecologists. Green-Top Guideline No. 37. Thromboprophylaxis during pregnancy, labour and after vaginal delivery. London: RCOG; 2004. 37. Pre-eclampsia Community Guideline Development Group. Pre-eclampsia community guideline (PRECOG). Middlesex: Action on Pre-Eclampsia (APEC); 2004. 38. Bhattacharya S, Campbell DM, Liston WA, et al. Effect of body mass index on pregnancy outcomes in nulliparous women delivering singleton babies. BMC Publ Health 2007;7:168. 39. Bianco AT, Smilen SW, Davis Y, et al. Pregnancy outcome and weight gain recommendations for the morbidly obese woman. Obstet Gynecol 1998;91:60–4. 40. Crowther CA, Hiller JE, Moss JR, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med 2005;352:2477–86. 41. National Institute for Health and Clinical Excellence (NICE). Diabetes in pregnancy: Management of diabetes and its complications from pre-conception to the postnatal period. London: NICE; 2008. 42. Duckitt K, Harrington D. Risk factors for pre-eclampsia at antenatal booking: systematic review of controlled studies. Br Med J 2005;330(7491):549–50. 43. Sattar N, Clark P, Holmes ANN, et al. Antenatal waist circumference and hypertension risk. Obstet Gynecol 2001;97:268–71. 44. Weiss JL, Malone FD, Emig D, et al. Obesity, obstetric complications and cesarean delivery rate – a population-based screening study. Am J Obstet Gynecol 2004;190:1091–7. 45. Nuthalapaty FS, Rouse DJ, Owen J. The association of maternal weight with cesarean risk, labor duration, and cervical dilation rate during labor induction.
46. 47.
48.
49. 50.
51.
52.
53. 54. 55.
107
Obstet Gynecol 2004;103:452–6 [Published erratum in Obstet Gynecol 2004 May; 103(5 Pt 1): 1019.]. National Institute for Health and Clinical Excellence (NICE). Intrapartum care: care of healthy women and their babies during childbirth. London: NICE; 2007. Prendiville WJ, Elbourne D, McDonald S. Active versus expectant management in the third stage of labour. Cochrane Database Syst Rev 2000;(3) [Update of Cochrane Database Syst Rev 2000;(2):CD000007.]. Myles TD, Gooch J, Santolaya J. Obesity as an independent risk factor for infectious morbidity in patients who undergo cesarean delivery. Obstet Gynecol 2002;100(5 Pt 1):959–64. National Institute for Health and Clinical Excellence. Caesarean section. London: Royal College of Obstetricians and Gynaecologists; 2004. Mok E, Multon C, Piguel L, et al. Decreased full breastfeeding, altered practices, perceptions, and infant weight change of prepregnant obese women: a need for extra support. Pediatrics 2008;121:e1319–24. National Institute for Health and Clinical Excellence. Antenatal care: routine care for the healthy pregnant woman. London: Royal College of Obstetricians and Gynaecologists; 2008. Leermakers EA, Anglin K, Wing RR. Reducing postpartum weight retention through a correspondence intervention. Int J Obes Relat Metab Disord 1998;22: 1103–9. O’Toole ML, Sawicki MA, Artal R. Structured diet and physical activity prevent postpartum weight retention. J Women’s Health (Larchmt) 2003;12:991–8. Kim C, Newton KM, Knopp RH. Gestational diabetes and the incidence of type 2 diabetes: a systematic review. Diabetes Care 2002;25:1862–8. Orozco LJ, Buchleitner AM, Gimenez-Perez G, et al. Exercise or exercise and diet for preventing type 2 diabetes mellitus. Cochrane Database Syst Rev 2008;(3). CD003054.