Spatula-assisted deliveries: a large cohort of 1065 cases

Spatula-assisted deliveries: a large cohort of 1065 cases

European Journal of Obstetrics & Gynecology and Reproductive Biology 151 (2010) 46–51 Contents lists available at ScienceDirect European Journal of ...

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European Journal of Obstetrics & Gynecology and Reproductive Biology 151 (2010) 46–51

Contents lists available at ScienceDirect

European Journal of Obstetrics & Gynecology and Reproductive Biology journal homepage: www.elsevier.com/locate/ejogrb

Spatula-assisted deliveries: a large cohort of 1065 cases Isabelle Boucoiran a,c,*, Laure Valerio b,c, Abdolreza Bafghi a,c, Jerome Delotte a,c, Andre´ Bongain a,c a

Department of Gynecology, Obstetrics and Reproductive Medicine, Nice University Hospital, Nice, France Department of Public Health, Nice University Hospital, Nice, France c Department Medicine, University of Nice Sophia Antipolis, Nice, France b

A R T I C L E I N F O

A B S T R A C T

Article history: Received 17 August 2009 Received in revised form 9 March 2010 Accepted 29 March 2010

Objective: To analyze neonatal and maternal complications of operative vaginal delivery using spatulas. Study design: We conducted a retrospective observational study of 1065 consecutive spatula-assisted deliveries at Nice University Hospital from 2003 through 2006, excluding stillbirths and breech deliveries. After univariate analysis, we performed logistic regression analysis to assess risk factors for severe perineal injuries and vaginal lacerations. Results: The success rate was 98.2%. Vaginal tears occurred in 23.7% of patients. The rate of third and fourth degree perineal injuries was 6.2%. No severe neonatal complication directly related to extraction was noted. Nulliparity, shoulder dystocia and absence of episiotomy were independently associated with an elevated risk of anal sphincter damage. Nulliparity and absence of episiotomy were significantly and independently associated with an increased incidence of vaginal tears. Conclusion: Rates of perineal injuries, failure and neonatal complications observed with spatulas were similar to those reported in the literature with other instruments for operative vaginal delivery. ß 2010 Elsevier Ireland Ltd. All rights reserved.

Keywords: Obstetrical extraction Spatulas Perineal injury Birth injuries Episiotomy

1. Introduction The purpose of instrumental delivery is to help women give birth to a healthy child by the vaginal route and to guarantee the lowest possible neonatal and maternal morbidity. However, obstetrical extraction poses an increased risk of birth injuries [1] and of maternal perineal injuries. The rate of operative vaginal delivery according to different countries varies between 10 and 15% [2,3]. Forceps and vacuum extractors are the most widely used instruments [4,5]. Spatulas are less commonly used unarticulated forceps but they have become the preferred instrument in several French institutions [6–11] and, according to our knowledge, in some European, African and Latin American countries [12,13]. No recent data are available concerning their current use in these countries. Two types of spatula are available (Fig. 1): Thierry’s spatulas (1950) and Teissier’s spatulas (1971). Both consist of two independent and symmetric branches which include a shank, a handle and the spatula itself, but Teissier’s spatulas are shorter and preferred for preterm deliveries [14]. Their use is based on the principle of two independent levers, which

* Corresponding author at: Department of Obstetrics and Gynecology (Pr Bongain), Hoˆpital l’Archet 2, 151 Rte de St-Antoine de Ginestie`re, 06202 Nice Cedex 3, France. Tel.: +33 492036052; fax: +33 492036580. E-mail address: [email protected] (I. Boucoiran). 0301-2115/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejogrb.2010.03.024

extend the hands of the obstetrician. The fetal head is propelled forward without being squeezed between the spatulas (Fig. 2). Delivery-related perineal lesions are considered the major risk factor for urinary and fecal incontinence [15]. During the postpartum period these lesions are associated with increased pain and infection (abscess, recto-vaginal fistula) [16]. Diagnosis and treatment of severe perineal injuries do not appear to avoid resulting sequelae [17]. Thus primary prevention should be prioritised. Although spatulas are the method of choice for operative vaginal delivery in several institutions [6–11], data on the risk of using spatulas for extraction and the resulting impact on the maternal perineum remain sparse. The aim of this study was to assess perineal and vaginal injuries and their risk factors, neonatal complications and the success rate of the use of spatulas. 2. Materials and methods 2.1. Study design This retrospective observational study was conducted in Nice University Hospital, France, a tertiary care obstetrics department where spatula-assisted delivery is the standard method of instrumental vaginal delivery. We reviewed all deliveries involving the use of spatulas between January 2003 and December 2006, followed by pediatric and maternal monitoring over a 4-day period. Our study was carried out in accordance with the

I. Boucoiran et al. / European Journal of Obstetrics & Gynecology and Reproductive Biology 151 (2010) 46–51

Fig. 1. Teissier’spatulas (above), Thierry’spatulas (below) (photos by G. Teissier). Spatulas provide a large contact surface with the fetal head and anatomic handles.

World Medical Association guidelines laid down in the Helsinki Declaration. Inclusion was restricted to all attempts at vertex operative vaginal delivery by Thierry or Teissier spatulas, beyond 24 weeks of gestation, regardless of fetal head position or parity. Spatula failures were defined as the inability to deliver the fetus with the initial use of spatulas, leading to the use of a second instrument or a caesarean section. They were included in the study. Breech delivery and stillbirths were excluded. We also excluded cases where spatulas were not the first instrument used during delivery. 2.2. Data source All cases were identified within the hospital delivery register. Information was obtained from the patients’ and their children’s

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medical records. Circumstances of delivery had been systematically entered in the computerized medical record by the physician performing the delivery. According to the Guidelines of the Society of Obstetricians and Gynaecologists of Canada [18] and the French College of Obstetricians and Gynaecologists [19], delayed pushing was preferred in the management of the second stage of labour (women did not push during the second stage of labour until they had a strong urge to push or until 2 h had passed). The decision to perform instrumental extraction was made by the attending physician based on the standard indications [20]: engaged fetal head with (i) non-reassuring fetal status according to fetal heart monitoring or scalp lactate, (ii) lack of progression during the second stage of labor (total duration of expulsive efforts >30 min) or (iii) maternal contraindication to expulsive efforts. Fetal head position was determined by transvaginal digital examination. Operative vaginal deliveries were performed by attending physicians or residents under the responsibility of an attending physician who was always present in the delivery room. No operative rotational procedure was performed. Mediolateral episiotomy was used to assist extraction if necessary. The decision to change the extraction device or to perform caesarean section rested on the attending physician. 2.3. Variables Recorded maternal characteristics included age, ethnicity, parity, history of operative vaginal delivery, caesarean section and perineal trauma, diabetes, and body mass index before pregnancy and at the time of delivery. The following exposure variables concerning labor and delivery were reviewed: term of pregnancy, labor induction, type of analgesia, duration of first and second stages of labor, fetal head position, indication for operative vaginal delivery, shoulder dystocia, and episiotomy. The main outcome variable was perineal injury, identified according to the World Health Organization International Classification of Diseases (ICD) criteria [21]. 2.3.1. Injuries without episiotomy The following four categories of perineal injuries were considered: (i) first degree: simple perineal and vaginal laceration (ICD O70.0); (ii) second degree: laceration of the perineal muscles (ICD O70.1); (iii) third degree: lesion of the external anal sphincter (ICD O70.2); (iv) fourth degree: involvement of both the anal sphincter and anorectal mucosa (ICD O70.3). We defined severe perineal injury as third and fourth degree laceration. Vaginal tears, namely laceration of the vaginal mucosa, were reported even when they were associated with perineal injury.

Fig. 2. Spatulas are two independent levers taking support on the fetal malar bones (1) and maternal perineum (2) (from Fournie´ A. et Parant O. Spatules de Thierry. Encycl Me´d Chir (Elsevier SAS, Paris), Obste´trique, 5-095-A-10, 2003, 4 p.).

2.3.2. Injuries associated with episiotomy When episiotomy extended towards the perineum, the perineal injuries were defined as follows: (i) second degree: laceration of the perineal muscles (ICD O70.1); (ii) third degree: lesion of the external anal sphincter (ICD O70.2); (iii) fourth degree: involvement of both the anal sphincter and anorectal mucosa (ICD O70.3). When the episiotomy extended towards the vagina, a vaginal tear was diagnosed. Neonatal outcomes of interest were birth weight, Apgar score at 1, 5 and 10 min, admission to a neonatal special care unit, cephalohematoma, scalp bruises and lacerations, orthopedic trauma, facial nerve paresis, brachial nerve injury and perinatal death. Newborns with birth weight above 4000 g were considered macrosomic. The pediatricians who examined the newborns were aware of the circumstances of the delivery.

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Fig. 3. Only cases where spatulas were the initially selected instrument were included.

2.4. Statistical analysis Data were anonymously centralized in a database (Microsoft Accessß) and coherence control was conducted for all variables. First, a descriptive analysis of population characteristics, rate of spatula failure, and rate of maternal and neonatal complications was performed. Then we conducted univariate analyses to identify factors associated with severe perineal injury and vaginal tears (ANOVA, Fisher’s exact tests, Chi squared). We finally ran stepwise selections of a priori predictive factors and factors associated with a significance level below 0.20 to fit multivariate logistic regression models. All tests were two-sided, with a 0.05 level of significance. The statistical analysis was conducted using SPPSß software, 11.0.1 (SPSSß Inc., 1989–2001).

occipito-posterior (OP) position at delivery (68.4%). These failures did not lead to severe perineal injury nor neonatal complications. Teissier’s spatulas were used in 14 cases among which 71.4% were preterm deliveries. This did not allow us to analyze these cases separately. 3.1. Perineal injuries Fifty-eight women (5.4%) had neither perineal lesion nor episiotomy. Episiotomy was performed in 930 (87.3%) women. Table 1 Obstetric and delivery characteristics of maternal population. Characteristic

3. Results Of 9822 deliveries during the study period, a total of 1065 spatula-assisted instrumental deliveries were analyzed (Fig. 3). Most patients were nulliparous (n = 878, 82.4%) and predominantly Caucasian (n = 698, 65.5%) with a mean age of 28.7 years. Our study included 42 twin pregnancies where at least one of the twins was extracted using spatulas. Delivery occurred at a mean gestational age of 39.7 weeks with 6.9% preterm deliveries (under 37 weeks). Two hundred and forty-seven (23.2%) patients had labor induction. Labor and delivery occurred under epidural anesthesia (93.2%), intravenous narcosis (1.7%), local anesthesia (1.9%) or without anesthesia (3.2%). The main indications for extraction were prolonged second stage of labor and/or non-reassuring fetal status (Table 1). Expulsion was in the occipito-posterior position in 149 cases (14.0%). Shoulder dystocia occurred in 56 cases (5.3%). Spatulaassisted extraction was successful in 98.2% of the cases. Among the 19 cases of failure, 15 women underwent caesarean section, 3 had vacuum-assisted vaginal delivery and 1 had forcep-assisted vaginal delivery. Thirteen cases of failure were related to

Obstetric history Instrumental delivery, n (%) Caesarean section, n (%) Perineal injury, n (%)

n = 1065 47 (4.4) 63 (5.9) 81 (7.6)

Labor Induction, n (%) Mean duration of second stage  SD, mn Second stage of labor >120 min, n (%)

247 (23.2) 84.6  61 338 (31.8)

Indication of extraction Lack of progression, n (%) Lack of progression and fetal status, n (%) Non-reassuring fetal status, n (%) Maternal contraindication for EEa, n (%) Fetal protectionb, n (%) Others, n (%)

505 311 229 8 5 7

Station Mid, n (%) Low, n (%) Outlet, n (%)

39 (3.7) 923 (86.6) 102 (9.6)

a

(47.4) (29.2) (21.5) (0.8) (0.5) (0.6)

EE: expulsive efforts. Following the Guidelines of the French College of Obstetricians and Gynaecologists, extractions by spatulas were sometimes indicated for fetal protection in case of preterm delivery, according to physician evaluation. b

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Table 2 Risk factors for severe perineal injury. Severe perineal injury

No (n = 999)

Yes (n = 66)

p-Valuea

ORa (95% CI)b

Nulliparous, n (%) Occiput posterior expulsion, n (%) Shoulder dystocia, n (%) No episiotomy, n (%)

819 135 47 121

59 14 9 14

0.125 0.097 0.002 0.031

2.35 2.20 3.44 2.26

(82.0) (13.5) (4.7) (12.1)

(89.4) (21.2) (13.6) (21.2)

(1.03–5.36) (0.98–3.44) (1.59–7.46) (1.19–4.29)

a

ANOVA used to compare continuous variables between groups, and Chi2 test for discrete variables. ORa: logistic regression adjusted odds ratio (punctual estimate and 95% confidence interval); reference categories are: multiparous, occiput anterior expulsion, no shoulder dystocia, episiotomy performed. b

Perineal tears occurred in 167 (15.7%) women, of which 29 were first degree, 72 second degree, 61 third degree and 5 fourth degree, i.e. 6.2% sustained severe perineal tears. Two hundred and fiftytwo women (23.7%) had a vaginal tear, 16 (1.5%) a periurethral tear and five (0.5%) a cervical tear. Among the 149 women who delivered in the OP position, 14 (21.2%) and 40 (15.9%) suffered from severe perineal injury and from vaginal tears, respectively. Perineal ecchymosis was identified in 74 patients, among whom two resulted in vaginal thrombus. There was no significant difference in age, gestational age, body mass index, prevalence of diabetes, prevalence of induced labor and type of anesthesia between women with or without severe perineal injuries. Factors significantly associated with an increased risk of severe perineal injury (Table 2) were shoulder dystocia (p = 0.002) and lack of episiotomy (p = 0.031). In nulliparous women, severe perineal injuries occurred in 5.9% of deliveries when episiotomy was performed, and in 13.8% in the absence of episiotomy (p = 0.05). In multiparous women, there was no such difference (3.6% vs. 4.2%, p = 0.858). In the final logistic regression model (Table 2), nulliparity, shoulder dystocia and lack of episiotomy were significantly and independently associated with the presence of severe perineal injury. After univariate analysis, gestational age, parity, absence of episiotomy and birth weight were significantly associated with the presence of a vaginal tear (Table 3). Multivarious analysis confirmed a significantly and independently greater incidence of vaginal tears among nulliparous women and in the absence of episiotomy. 3.2. Neonatal outcomes Mean birth weigh was 3297 g and 7% of newborns were macrosomic. No severe neonatal complication directly related to extraction was observed. The Apgar score at one minute was below three in 13 cases (1.2%) and remained below seven at 5 min in 16 cases (1.5%). According to the newborns’ medical records, no transfer to the neonatal special care unit (83 cases, 7.8%) was related to the

spatula-assisted extraction. Neonatal complications included: (i) instrument-related bruises: 13.0%, (ii) orthopedic injury: 0.7% (fractured clavicle or humerus), (iii) facial nerve paresis: 0.3%, (iv) brachial plexus injury: 0.3% and (v) cephalematoma: 0.7%. There were four cases (0.4%) of early neonatal death (<24 h after birth). Two of them were the consequence of severe malformations diagnosed before birth. One newborn died due to extreme prematurity. The fourth child was born at 38 weeks by spatula-assisted delivery because of prolonged second stage of labor; he died a few seconds after delivery following vernix caseosa aspiration syndrome. 4. Comments This large study was designed to estimate the immediate maternal and neonatal effects of spatula-assisted deliveries in a university hospital. The rate of operative vaginal deliveries during our study period (12.1%) is similar to that reported by the French medical practice research institute (12.8% in 2003) [22]. In all studies focusing on spatulas [6–13], including our own, failure rates are lower (0–5.2%) than those reported for vacuumand forcep-assisted deliveries (11.5 and 7%, respectively) [5]. Furthermore these failures appear to have no major consequences, in particular severe perineal lesions and fetal trauma, whereas the literature reports an increased risk of these complications when two extraction instruments are used in succession (forceps and vacuum) [23]. In our study, the incidence of severe perineal injuries associated with spatula-assisted deliveries (6.2%) is slightly higher than that reported in other studies concerning spatulas, which range from 3.0 to 5.4% [6–11]. This difference is probably due to (i) the fact that our study was conducted in a university hospital with a residency training program in obstetrics and (ii) differences in third degree perineal tear definition. Indeed, in accordance with WHO criteria [21], our study takes all lesions of the anal sphincter into account, including even partial lesions (involving less than 50% thickness) of the sphincter ani externus muscle.

Table 3 Risk factors for vaginal laceration. Vaginal laceration Mean BMIc at time of delivery, kg m Nulliparous, n (%) Twin pregnancy, n (%) Obstetric history Instrumental delivery, n (%) Perineal injury, n (%) Labor and delivery Mean gestational age, week Preterm birth (<37 weeks), n (%) Absence of episiotomy, n (%) Mean birth weight, g a

2

No (n = 813)

Yes (n = 252)

p-Valuea

27.7 655 (80.5) 40 (4.9)

28.4 223 (88.5) 2 (0.8)

0.002 0.004 0.003

1.04 (1.00–1.07) 2.29 (1.46–3.60) 0.34 (0.07–1.57)

43 (5.3) 68 (8.7)

4 (1.6) 13 (5.2)

0.012 0.071

0.54 (0.16–1.79) 0.72 (0.30–1.75)

39.58 64 (7.9) 91 (11.2) 3257

40.04 9 (3.6) 44 (17.5) 3428

0.002 0.018 0.009 0.001

ORa (95% CI)b

1.02 1.29 2.20 1.00

(0.90–1.16) (0.47–3.56) (1.44–3.34) (1.00–1.001)

ANOVA used to compare continuous variables between groups, and Chi2 test for discrete variables. ORa: logistic regression adjusted odds ratio (punctual estimate and 95% confidence interval); reference categories for discrete variables are: multiparous, no case history, single birth, no preterm birth, episiotomy performed. c BMI: body mass index. b

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Our results appear similar to those concerning vacuum and forceps extraction [5]. They also confirm the results of a cohort study comparing spatula- and vacuum-assisted deliveries [11] which found no difference in incidence of sphincter tears. Risk factors for severe perineal injuries have been amply documented in the literature concerning spatulas [6,24] and other devices [16,25,26] and are the same overall: nulliparity with a relative risk of 10, fetal occipito-posterior position, shoulder dystocia. But contrary to published reports [16,27] our study did not identify macrosomia as an independent risk factor for severe perineal injury. The rate of vaginal tears in our study (23.7%) is consistent with previous studies concerning spatula-assisted deliveries [8–10] and globally higher than rates of vaginal tears associated with extraction by forceps [23] and by vacuum [28]. In our study, the frequency of cervical tears (0.5%) was comparable to that related to vacuum and forceps extractions [23]. According to current guidelines for operative vaginal birth in several countries [18,29], routine episiotomy is not necessary for assisted vaginal birth. Of interest is our finding of a protective effect of episiotomy on the occurrence of severe perineal and vaginal tears in spatula-assisted extraction. In a recent work concerning spatulas, De Troyer et al. [6] concluded that episiotomy was globally protective against perineal injuries. The role of episiotomy in vacuum or forceps deliveries is debated, depending on the type of episiotomy (mildline or mediolateral), prevalence of instrumental delivery and prevalence of episiotomy [25,30,31]. We think that the relevance of mediolateral episiotomy in spatulaassisted deliveries is due to the mechanical principle involved. Indeed, the spatulas work by stretching soft tissues and propelling the fetal head forward. Mediolateral episiotomy appears to decrease direct trauma of perineal tissues by the spatula handles. Regardless of the extraction device used, operative vaginal deliveries are globally associated with a higher rate of neonatal complications than spontaneous deliveries [1,9,23]. The rates of transfer to a neonatal special care unit, low Apgar score and perinatal death in our study are similar to those reported in other studies concerning operative vaginal deliveries [5,32]. To our knowledge, only one case of skull fracture due to extraction by Thierry’s spatulas has been published [8]. This type of complication has also been described in studies concerning vacuum-assisted and forcep-assisted delivery [1]. Concerning neonatal morbidity, the spatulas appear safer than the other extraction devices, thanks to differences in obstetrical mechanisms. Indeed, the two spoons do not pull or lock on the fetal head but propel it forward by lying against the malar bone, thus avoiding compression. According to our knowledge this study is the largest concerning spatula-assisted deliveries. Its major limitation is related to its retrospective nature but its strength lies in the quality and completeness of recorded medical data. More information related to maternal complications other than perineal injuries, especially haemorrhage, would have been useful to further evaluate the consequences of the use of spatulas. But these data were not computerized and not always avalaible, which makes this information difficult to interpret. Another limitation of the validity of our study is that we do not report direct comparison of spatulas with other instruments. Such a study would be difficult to design as operators would need to be equally comfortable with both instruments and have the same indications for each. As a conclusion, our results, in accordance with other studies concerning the use of spatulas, show lower neonatal morbidity than reported with other extraction devices. The findings of this study show that the risk of severe perineal injuries with spatulas is equivalent to that reported with other extraction instruments, especially when episiotomy is conducted on nulliparous women, but vaginal tears are more common. Immediate consequences of the lesions associated with spatula-assisted deliveries are still to

be evaluated, especially haemorrhage and pain. Persistent anal symptoms after instrumental delivery with spatulas appear as frequent as after delivery with forceps or vacuum [33]. Other longterm outcomes such as urinary incontinence, persistence of pain, sexual activities and prolapse need to be evaluated. Acknowledgements V. Looman for her help in data collection. G. Teissier for his helpful discussion of obstetrical mechanisms and his own experience with spatulas. B. Dunais for her precious help during the translation process. References [1] Doumouchtsis SK, Arulkumaran S. Head trauma after instrumental births. Clin Perinatol 2008;35(March (1)):69–83. viii. [2] Lola Jean Kozak JDW. U.S. trends in obstetric procedures, 1990–2000. Birth 2002;29(3):157–61. [3] Dupuis O, Silveira R, Redarce T, Dittmar A, Rudigoz RC. Instrumental extraction in 2002 in the ‘‘AURORE’’ hospital network: incidence and serious neonatal complications. Gynecol Obstet Fertil 2003;31(November (11)):920–6. [4] Hillier CE, Johanson RB. Worldwide survey of assisted vaginal delivery. Int J Gynaecol Obstet 1994;47(November (2)):109–14. [5] Johanson RB, Menon BK. Vacuum extraction versus forceps for assisted vaginal delivery. Cochrane Database Syst Rev 2000;2. CD000224. [6] De Troyer J, Bouvenot J, D’Ercole C, Boubli L. Instrumental extraction with Thierry’s spatula: 166 cases. J Gynecol Obstet Biol Reprod (Paris) 2005;34(December (8)):795–801. [7] Mazouni C, Bretelle F, Collette E, Heckenroth H, Bonnier P, Gamerre M. Maternal and neonatal morbidity after first vaginal delivery using Thierry’s spatulas. Aust N Z J Obstet Gynaecol 2005;45(October (5)):405–9. [8] Guyomar J. Obstetrical value of Thierry’s spatules. Results of 1,000 applications. Rev Fr Gynecol Obstet 1965;60(December (12)):775–83. [9] Maisonnette-Escot Y, Riethmuller D, Chevriere S, et al. Thierry’s spatula instrumental extraction: a study of foetal–maternal morbidity. Gynecol Obstet Fertil 2005;33(April (4)):208–12. [10] Fournie A. The use of Thierry’s spatula at the University hospital center in Toulouse in 1988. Rev Fr Gynecol Obstet 1990;85(October (10)):553–6. [11] Menard JP, Provansal M, Heckenroth H, Gamerre M, Bretelle F, Mazouni C. Maternal morbidity after Thierry’s spatulas and vacuum deliveries. Gynecol Obstet Fertil 2008;36(June (6)):623–7. [12] Lloyd FP, Geisler HE, Lushbaugh H. Unarticulated forceps in operative obstetrics. The spatulas of thierry. Am J Obstet Gynecol 1964;90(December):925–8. [13] Perez JO. The spatules of Thierry. Am J Obstet Gynecol 1957;74(December (6)):1215–7. [14] Simon-Toulza C, Parant O. Spatulas: description, obstetrical mechanics, indications and contra-indications. J Gynecol Obstet Biol Reprod (Paris) 2008;37(December (Suppl. 8)):S222–30. [15] Kamm MA. Obstetric damage and faecal incontinence. Lancet 1994;344(September (8924)):730–3. [16] Christianson LM, Bovbjerg VE, McDavitt EC, Hullfish KL. Risk factors for perineal injury during delivery. Am J Obstet Gynecol 2003;189(July (1)): 255–60. [17] Mahony R, Behan M, Daly L, Kirwan C, O’Herlihy C, O’Connell PR. Internal anal sphincter defect influences continence outcome following obstetric anal sphincter injury. Am J Obstet Gynecol 2007;196(March (3)). p. 217e1–217e5. [18] SOGC. Guidelines for operative vaginal birth. Number 148, May 2004. Int J Gynaecol Obstet 2005;88(February (2)):229–36. [19] Sentilhes L, Gillard P, Descamps P, Fournie A. Indications and prerequisites for operative vaginal delivery: when, how and where? J Gynecol Obstet Biol Reprod (Paris) 2008;37(December (Suppl. 8)):S188–201. [20] ACOG practice bulletin operative vaginal delivery. Int J Gynecol Obst 2001; 74(1):69. [21] WHO. International classification of diseases, 10th revision (ICD-10-O70). Geneva, Switzerland: WHO; 1996. [22] Mamelle N, Vendittelli F, Riviere O, et al. Prenatal health in 2002–2003. Survey of medical practice. Results from the Audipog sentinel network. Gynecol Obstet Fertil 2004;32(August (Spec No 1)):4–22. [23] Gardella C, Taylor M, Benedetti T, Hitti J, Critchlow C. The effect of sequential use of vacuum and forceps for assisted vaginal delivery on neonatal and maternal outcomes. Am J Obstet Gynecol 2001;185(October (4)):896–902. [24] Courtois L, Becher P, Maticot-Baptista D, et al. Instrumental extractions using Thierry’s spatulas: evaluation of the risk of perineal laceration according to occiput position in operative deliveries. J Gynecol Obstet Biol Reprod (Paris) 2008;37(May (3)):276–82. [25] De Leeuw JW, De Wit C, Kuijken JP, Bruinse HW. Mediolateral episiotomy reduces the risk for anal sphincter injury during operative vaginal delivery. BJOG Int J Obstet Gynaecol 2008;115(1):104–8. [26] Damron DP, Capeless EL. Operative vaginal delivery: a comparison of forceps and vacuum for success rate and risk of rectal sphincter injury. Am J Obstet Gynecol 2004;191(September (3)):907–10.

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