- Email: [email protected]
329: Preterm birth classification: Is birth certificate data adequate?
Poster Session II
ajog.org CDs: universal GBS screening at 35 weeks’ gestation or no screening. In the universal screening strategy, all women found to be GBS positive who presented in labor prior to scheduled repeat CD received antibiotic prophylaxis. In the no screening strategy, women who presented in labor received antibiotics based on risk based criteria (i.e. antibiotics if < 37 weeks’). Neonates born to women colonized with GBS who did not receive antibiotics in labor were at risk for early-onset GBS disease, disability and death. Based on published literature, we assumed a GBS prevalence of 22.8% (range 18-30%), that 26.6% (range 13.5-50%) of women labor between 35 weeks’ and their scheduled CD, and that 97.7% (range 30-100%) of women intending to have a CD had a CD. The primary outcome was cost per neonatal quality adjusted life year (QALY) gained with a cost-effectiveness threshold of $100,000 USD per QALY gained. Additional outcomes obtained included the number needed to screen and the cost required to prevent neonatal morbidity (earlyonset GBS disease, disability and death). One-way sensitivity and Monte-Carlo analyses were used to evaluate the robustness of the results. RESULTS: In the base case, universal GBS screening in women intending to have a repeat CD is not cost effective compared to no screening, costing $139,620 per neonatal QALY gained. The cost to prevent each type of neonatal morbidity exceeds $500,000 (Table). The model is highly sensitive to several variables; if >28% of women are GBS positive, >32% of women labor prior to their repeat CD, or >20% of women deliver vaginally, universal screening becomes cost effective (Figure). CONCLUSION: Universal GBS screening in women intending to have a repeat CD is not cost effective in the general population. However, in women at high risk of laboring prior to their scheduled CD, women who may ultimately opt for a vaginal delivery, or populations with a high GBS prevalence, GBS screening is cost effective. Number Needed to Screen and Cost to Prevent One Adverse Outcome from GBS
strategies that optimize maternal and neonatal outcomes. We sought to examine the effectiveness of such a protocol by comparing outcomes before and after its introduction. STUDY DESIGN: This is a prospective observational cohort study of GDM cases from a tertiary center over 5 years. Two models of prenatal care were compared. In the first (2009-2011) all new GDM cases were transferred from routine prenatal care to a combined obstetric/endocrinology clinic. Management comprised lifestyle and dietary intervention followed by insulin therapy where necessary. In the second (2012-2013) all cases commenced the same dietary and lifestyle intervention and attended for midwife-led glucose monitoring. Prenatal care otherwise remained routine. If glycemic control was inadequate care was escalated to the combined obstetric/endocrinology clinic. A comparison of outcomes between the two models of care was performed. RESULTS: During the study period there were 1558 cases of GDM, 916 from 2009-11,(Model 1) and 642 in 2012-13 (Model 2). There were no differences between the two models in the need for insulin therapy (44%[399/916] vs. 44%[286/642], p¼0.7). Rates of induction of labor were similar (35%[324/916] vs. (36%[234/642], p¼0.6), as were cesarean (45%[417/916] vs. 47%[305/642], p¼0.4) and operative vaginal delivery (14%[129/916] vs. 14%[87/642], p¼0.8) rates. No differences in birthweight >4kg (17%[156/916] vs. 19%[120/642], p¼0.4) or >4.5kg (4%[36/916] vs. 4%[26/642], p¼0.9) were noted. There was no significant difference in neonatal unit admission rates (16.5%[151/916] vs. 20%[131/642], p¼0.05). There were 3 stillbirths and 7 cases of HIE in the first model, with 1 stillbirth and no HIE recorded in the second time period. CONCLUSION: The implementation of a stratified model of care in GDM is not associated with excess maternal or neonatal risk, and may represent a more efficient and cost effective use of limited healthcare resources.
Outcome Variable
Number Needed to Screen Cost to Prevent One Case, 2015 USD
Early-Onset GBS Disease
32,636
$520,288
329 Preterm birth classification: Is birth certificate data adequate?
Neonatal Death
1,327,580
$21,165,012
Molly J. Stout1, George A. Macones1, Methodius G. Tuuli1
Any GBS-Related Disability 128,361
1
Washington University in St. Louis, Saint Louis, MO
$2,046,400
OBJECTIVE: The highly diverse phenotypes of preterm birth (PTB)
328 A stratified approach to the management of gestational diabetes - an effective alternative model of care? Jennifer M. Walsh1, Jessica Colby Milley1, Laura C. Gilroy1, Siobhan Corcoran1 1
Royal College of Surgeons in Ireland, Dublin, Ireland
OBJECTIVE: Rates of gestational diabetes (GDM) are increasing
worldwide, a trend that is likely to continue with rising obesity rates and lower threshold diagnostic criteria. This has significant resource implications; healthcare systems need to develop cost effective
may contribute to lack of progress in understanding of pathophysiologic pathways and prevention strategies. Traditional classification as “spontaneous” (S) or “indicated” (I) is the most basic attempt at separating PTB subtypes. We previously published that the accuracy of classification is influenced by the type of hospital records used and the experience of the reviewer. Because perinatal epidemiologic investigations may occur across hospital systems, we sought to investigate whether state birth certificate (BC) data can be used to accurately classify PTB into S and I subtypes. STUDY DESIGN: We performed a cross-sectional study where the gold standard classification of S or I was achieved based on discussion and review of all pertinent medical record documents jointly by an MFM panel (MFM fellow, MFM junior faculty member, and senior MFM faculty member). Missouri birth certificates of the same patients were then blindly reviewed and classified as S or I. We estimated accuracy of classification based on birth certificates using the consensus from review of complete hospital record as the correct classification. RESULTS: 125 BCs were reviewed. Two (1.6% [95%CI 0.1%, 5.6%]) were unclassifiable based on information present in the BC. The overall accuracy was 67.5% (95%CI 58.4%, 75.6%) for the 123 classified. Classification was correct for 64.6% (95% CI 55.0%, 73.4%) of the S PTB subtype and 100% (95%CI 69.2%,
Supplement to JANUARY 2016 American Journal of Obstetrics & Gynecology
S185
Poster Session II 100%) for I PTB subtype, although by birth certificate data 40 patients with I PTB subtype were misclassified as S (FIGURE). The two that were unclassifiable based on birth certificate data were both subtype I by consensus. The most common error for the 40 I PTB misclassification was when delivery was preceded by “premature rupture of membranes >12 hours” based on the birth certificate data. CONCLUSION: Correct classification of PTB subtype into S or I by birth certificate data is unreliable. Clinical information captured on state reported birth data is inadequate for classification of PTB.
ajog.org 0.62 (95% CI (0.51-0.77)], jaundice [OR 0.71 (95% CI (0.55-0.92)], and SGA [OR 0.69 (95% CI (0.50-0.97)]. CONCLUSION: Among pregnancies complicated by chronic hypertension, adolescent maternal age is associated with an increased risk of superimposed preeclampsia and infant death, but decreased risk of preterm delivery, cesarean section, neonatal jaundice, and SGA. These findings suggest a potential association between length of exposure to chronic hypertension and the risk of developing perinatal complications. This relationship should be further explored in future studies. Perinatal complications in women with chronic hypertension by maternal age, (%, *p-value<0.01) Perinatal Complication
Maternal Age <20 years, N=452
Maternal Age 20-35 years, N=12,163
Preterm Delivery
3.98
4.16
Superimposed preeclampsia
39.19*
26.11*
Eclampsia
0.22
0.07
Abruption
1.55
1.69
IUFD
0.88
0.89
Small for Gestational Age (<10th%)
10.77
11.15
Jaundice
20.8*
26.19*
Infant Death
0.89
0.54
Cesarean Delivery
40.93*
49.54*
Induction of Labor
32.96*
28.55*
331 Association of baseline proteinuria with adverse pregnancy outcomes in chronic hypertension 330 Maternal age and risk of perinatal complications in gravidas with chronic hypertension Christina A. Penfield1, Rachel A. Pilliod2, Tania F. Esakoff3, Amy M. Valent4, Aaron B. Caughey4 1
University of California, Irvine, Los Angeles, CA, 2Brigham and Women’s Hospital, Boston, MA, 3Cedars-Sinai Medical Center, Los Angeles, CA, 4 Oregon Health Sciences University, Portland, OR
OBJECTIVE: Chronic hypertension is associated with increased
adverse perinatal outcomes, yet it remains unclear whether maternal age modifies a patient’s risk for these complications. Our study evaluated the influence of adolescent age on the rates of adverse outcomes in pregnancies complicated by chronic hypertension. STUDY DESIGN: This is a retrospective cohort study using 2005-2008 linked hospital discharge and vital statistics records data of live births to women with chronic hypertension in California. Perinatal complications were compared between adolescent women (<20 years old) and adult women (aged 20-35 years) delivering between 24 and 42 weeks gestational age. Maternal outcomes examined include preterm delivery <32 weeks (PTD), superimposed preeclampsia (SPET), eclampsia, abruption, induction of labor (IOL), and cesarean section (CS). Perinatal and neonatal outcomes analyzed were neonatal jaundice, small for gestational age (SGA, defined as 10th percentile for gestational age), intrauterine fetal demise (IUFD), and infant death (within the first year of life). Bivariate and multivariate analyses were performed. RESULTS: We identified 21,959 women with chronic hypertension. Adolescents had higher rates of SPET and IOL, and lower rates of neonatal jaundice and CS than the adult population with chronic hypertension (Table). After controlling for maternal comorbidities and sociodemographic characteristics, adolescent age was an independent risk factor for infant death [OR 3.79 (95% CI (1.22-11.72)], and SPET [OR 1.39 (95% CI (1.17-1.65)], and also independently protective against PTD 0.57 [OR 0.57 (95% CI (0.32-0.99)], CS [OR
Spencer G. Kuper1, Alan T. Tita1, Mallory L. Youngstrom1, Ying Tang1, Joseph R. Biggio1, Lorie M. Harper1 1
University of Alabama at Birmingham, Center for Women’s Reproductive Health, Birmingham, AL
OBJECTIVE: While a urine protein:creatinine (PC) ratio of 0.3 is used to diagnose preeclampsia (PE), there is not an identified baseline PC that predicts the development of adverse outcomes. We examined the association between baseline proteinuria and adverse outcomes in women with chronic hypertension (CHTN). STUDY DESIGN: Retrospective cohort of all singletons with CHTN in a single tertiary center from 2000-2014 with assessment of baseline renal function 20 weeks gestation. Subjects were excluded for creatinine 1.2 mg/dL, anomalous fetuses and major medical problems other than diabetes. The primary outcome was PE with severe features <34 weeks. Secondary outcomes were severe PE at any gestational age (GA), any PE, preterm birth (PTB) < 35 weeks, composite neonatal outcome (perinatal death, assisted ventilation, cord pH < 7, 5-minute Apgar 3 and neonatal seizures) and small for gestational age (SGA). PE was defined by ACOG definitions requiring either proteinuria or abnormal serum labs in addition to hypertension. Receiver-operating characteristic (ROC) curves were used to estimate the association between baseline PC and the primary outcome. The Liu method was used to objectively determine a cut-point for PC; outcomes were compared between those with PC values above and below the cut-point using univariate and multivariate analyses. RESULTS: 739 women with CHTN had assessment of PC 20 completed weeks of gestation. The area under the ROC curve for early onset severe PE in women was 0.74(95%CI 0.65-0.83). The PC Liu cut-point for the development of severe PE was 0.12, which had a sensitivity and specificity of 69.6 and 76.5%, respectively. A PC 0.12 was significantly associated with an increased risk of any type of PE and PTB < 35 weeks. CONCLUSION: A baseline PC 0.12 in patients with CHTN and normal creatinine is associated with development of PE and PTB.
S186 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2016
ajog.org CDs: universal GBS screening at 35 weeks’ gestation or no screening. In the universal screening strategy, all women found to be GBS positive who presented in labor prior to scheduled repeat CD received antibiotic prophylaxis. In the no screening strategy, women who presented in labor received antibiotics based on risk based criteria (i.e. antibiotics if < 37 weeks’). Neonates born to women colonized with GBS who did not receive antibiotics in labor were at risk for early-onset GBS disease, disability and death. Based on published literature, we assumed a GBS prevalence of 22.8% (range 18-30%), that 26.6% (range 13.5-50%) of women labor between 35 weeks’ and their scheduled CD, and that 97.7% (range 30-100%) of women intending to have a CD had a CD. The primary outcome was cost per neonatal quality adjusted life year (QALY) gained with a cost-effectiveness threshold of $100,000 USD per QALY gained. Additional outcomes obtained included the number needed to screen and the cost required to prevent neonatal morbidity (earlyonset GBS disease, disability and death). One-way sensitivity and Monte-Carlo analyses were used to evaluate the robustness of the results. RESULTS: In the base case, universal GBS screening in women intending to have a repeat CD is not cost effective compared to no screening, costing $139,620 per neonatal QALY gained. The cost to prevent each type of neonatal morbidity exceeds $500,000 (Table). The model is highly sensitive to several variables; if >28% of women are GBS positive, >32% of women labor prior to their repeat CD, or >20% of women deliver vaginally, universal screening becomes cost effective (Figure). CONCLUSION: Universal GBS screening in women intending to have a repeat CD is not cost effective in the general population. However, in women at high risk of laboring prior to their scheduled CD, women who may ultimately opt for a vaginal delivery, or populations with a high GBS prevalence, GBS screening is cost effective. Number Needed to Screen and Cost to Prevent One Adverse Outcome from GBS
strategies that optimize maternal and neonatal outcomes. We sought to examine the effectiveness of such a protocol by comparing outcomes before and after its introduction. STUDY DESIGN: This is a prospective observational cohort study of GDM cases from a tertiary center over 5 years. Two models of prenatal care were compared. In the first (2009-2011) all new GDM cases were transferred from routine prenatal care to a combined obstetric/endocrinology clinic. Management comprised lifestyle and dietary intervention followed by insulin therapy where necessary. In the second (2012-2013) all cases commenced the same dietary and lifestyle intervention and attended for midwife-led glucose monitoring. Prenatal care otherwise remained routine. If glycemic control was inadequate care was escalated to the combined obstetric/endocrinology clinic. A comparison of outcomes between the two models of care was performed. RESULTS: During the study period there were 1558 cases of GDM, 916 from 2009-11,(Model 1) and 642 in 2012-13 (Model 2). There were no differences between the two models in the need for insulin therapy (44%[399/916] vs. 44%[286/642], p¼0.7). Rates of induction of labor were similar (35%[324/916] vs. (36%[234/642], p¼0.6), as were cesarean (45%[417/916] vs. 47%[305/642], p¼0.4) and operative vaginal delivery (14%[129/916] vs. 14%[87/642], p¼0.8) rates. No differences in birthweight >4kg (17%[156/916] vs. 19%[120/642], p¼0.4) or >4.5kg (4%[36/916] vs. 4%[26/642], p¼0.9) were noted. There was no significant difference in neonatal unit admission rates (16.5%[151/916] vs. 20%[131/642], p¼0.05). There were 3 stillbirths and 7 cases of HIE in the first model, with 1 stillbirth and no HIE recorded in the second time period. CONCLUSION: The implementation of a stratified model of care in GDM is not associated with excess maternal or neonatal risk, and may represent a more efficient and cost effective use of limited healthcare resources.
Outcome Variable
Number Needed to Screen Cost to Prevent One Case, 2015 USD
Early-Onset GBS Disease
32,636
$520,288
329 Preterm birth classification: Is birth certificate data adequate?
Neonatal Death
1,327,580
$21,165,012
Molly J. Stout1, George A. Macones1, Methodius G. Tuuli1
Any GBS-Related Disability 128,361
1
Washington University in St. Louis, Saint Louis, MO
$2,046,400
OBJECTIVE: The highly diverse phenotypes of preterm birth (PTB)
328 A stratified approach to the management of gestational diabetes - an effective alternative model of care? Jennifer M. Walsh1, Jessica Colby Milley1, Laura C. Gilroy1, Siobhan Corcoran1 1
Royal College of Surgeons in Ireland, Dublin, Ireland
OBJECTIVE: Rates of gestational diabetes (GDM) are increasing
worldwide, a trend that is likely to continue with rising obesity rates and lower threshold diagnostic criteria. This has significant resource implications; healthcare systems need to develop cost effective
may contribute to lack of progress in understanding of pathophysiologic pathways and prevention strategies. Traditional classification as “spontaneous” (S) or “indicated” (I) is the most basic attempt at separating PTB subtypes. We previously published that the accuracy of classification is influenced by the type of hospital records used and the experience of the reviewer. Because perinatal epidemiologic investigations may occur across hospital systems, we sought to investigate whether state birth certificate (BC) data can be used to accurately classify PTB into S and I subtypes. STUDY DESIGN: We performed a cross-sectional study where the gold standard classification of S or I was achieved based on discussion and review of all pertinent medical record documents jointly by an MFM panel (MFM fellow, MFM junior faculty member, and senior MFM faculty member). Missouri birth certificates of the same patients were then blindly reviewed and classified as S or I. We estimated accuracy of classification based on birth certificates using the consensus from review of complete hospital record as the correct classification. RESULTS: 125 BCs were reviewed. Two (1.6% [95%CI 0.1%, 5.6%]) were unclassifiable based on information present in the BC. The overall accuracy was 67.5% (95%CI 58.4%, 75.6%) for the 123 classified. Classification was correct for 64.6% (95% CI 55.0%, 73.4%) of the S PTB subtype and 100% (95%CI 69.2%,
Supplement to JANUARY 2016 American Journal of Obstetrics & Gynecology
S185
Poster Session II 100%) for I PTB subtype, although by birth certificate data 40 patients with I PTB subtype were misclassified as S (FIGURE). The two that were unclassifiable based on birth certificate data were both subtype I by consensus. The most common error for the 40 I PTB misclassification was when delivery was preceded by “premature rupture of membranes >12 hours” based on the birth certificate data. CONCLUSION: Correct classification of PTB subtype into S or I by birth certificate data is unreliable. Clinical information captured on state reported birth data is inadequate for classification of PTB.
ajog.org 0.62 (95% CI (0.51-0.77)], jaundice [OR 0.71 (95% CI (0.55-0.92)], and SGA [OR 0.69 (95% CI (0.50-0.97)]. CONCLUSION: Among pregnancies complicated by chronic hypertension, adolescent maternal age is associated with an increased risk of superimposed preeclampsia and infant death, but decreased risk of preterm delivery, cesarean section, neonatal jaundice, and SGA. These findings suggest a potential association between length of exposure to chronic hypertension and the risk of developing perinatal complications. This relationship should be further explored in future studies. Perinatal complications in women with chronic hypertension by maternal age, (%, *p-value<0.01) Perinatal Complication
Maternal Age <20 years, N=452
Maternal Age 20-35 years, N=12,163
Preterm Delivery
3.98
4.16
Superimposed preeclampsia
39.19*
26.11*
Eclampsia
0.22
0.07
Abruption
1.55
1.69
IUFD
0.88
0.89
Small for Gestational Age (<10th%)
10.77
11.15
Jaundice
20.8*
26.19*
Infant Death
0.89
0.54
Cesarean Delivery
40.93*
49.54*
Induction of Labor
32.96*
28.55*
331 Association of baseline proteinuria with adverse pregnancy outcomes in chronic hypertension 330 Maternal age and risk of perinatal complications in gravidas with chronic hypertension Christina A. Penfield1, Rachel A. Pilliod2, Tania F. Esakoff3, Amy M. Valent4, Aaron B. Caughey4 1
University of California, Irvine, Los Angeles, CA, 2Brigham and Women’s Hospital, Boston, MA, 3Cedars-Sinai Medical Center, Los Angeles, CA, 4 Oregon Health Sciences University, Portland, OR
OBJECTIVE: Chronic hypertension is associated with increased
adverse perinatal outcomes, yet it remains unclear whether maternal age modifies a patient’s risk for these complications. Our study evaluated the influence of adolescent age on the rates of adverse outcomes in pregnancies complicated by chronic hypertension. STUDY DESIGN: This is a retrospective cohort study using 2005-2008 linked hospital discharge and vital statistics records data of live births to women with chronic hypertension in California. Perinatal complications were compared between adolescent women (<20 years old) and adult women (aged 20-35 years) delivering between 24 and 42 weeks gestational age. Maternal outcomes examined include preterm delivery <32 weeks (PTD), superimposed preeclampsia (SPET), eclampsia, abruption, induction of labor (IOL), and cesarean section (CS). Perinatal and neonatal outcomes analyzed were neonatal jaundice, small for gestational age (SGA, defined as 10th percentile for gestational age), intrauterine fetal demise (IUFD), and infant death (within the first year of life). Bivariate and multivariate analyses were performed. RESULTS: We identified 21,959 women with chronic hypertension. Adolescents had higher rates of SPET and IOL, and lower rates of neonatal jaundice and CS than the adult population with chronic hypertension (Table). After controlling for maternal comorbidities and sociodemographic characteristics, adolescent age was an independent risk factor for infant death [OR 3.79 (95% CI (1.22-11.72)], and SPET [OR 1.39 (95% CI (1.17-1.65)], and also independently protective against PTD 0.57 [OR 0.57 (95% CI (0.32-0.99)], CS [OR
Spencer G. Kuper1, Alan T. Tita1, Mallory L. Youngstrom1, Ying Tang1, Joseph R. Biggio1, Lorie M. Harper1 1
University of Alabama at Birmingham, Center for Women’s Reproductive Health, Birmingham, AL
OBJECTIVE: While a urine protein:creatinine (PC) ratio of 0.3 is used to diagnose preeclampsia (PE), there is not an identified baseline PC that predicts the development of adverse outcomes. We examined the association between baseline proteinuria and adverse outcomes in women with chronic hypertension (CHTN). STUDY DESIGN: Retrospective cohort of all singletons with CHTN in a single tertiary center from 2000-2014 with assessment of baseline renal function 20 weeks gestation. Subjects were excluded for creatinine 1.2 mg/dL, anomalous fetuses and major medical problems other than diabetes. The primary outcome was PE with severe features <34 weeks. Secondary outcomes were severe PE at any gestational age (GA), any PE, preterm birth (PTB) < 35 weeks, composite neonatal outcome (perinatal death, assisted ventilation, cord pH < 7, 5-minute Apgar 3 and neonatal seizures) and small for gestational age (SGA). PE was defined by ACOG definitions requiring either proteinuria or abnormal serum labs in addition to hypertension. Receiver-operating characteristic (ROC) curves were used to estimate the association between baseline PC and the primary outcome. The Liu method was used to objectively determine a cut-point for PC; outcomes were compared between those with PC values above and below the cut-point using univariate and multivariate analyses. RESULTS: 739 women with CHTN had assessment of PC 20 completed weeks of gestation. The area under the ROC curve for early onset severe PE in women was 0.74(95%CI 0.65-0.83). The PC Liu cut-point for the development of severe PE was 0.12, which had a sensitivity and specificity of 69.6 and 76.5%, respectively. A PC 0.12 was significantly associated with an increased risk of any type of PE and PTB < 35 weeks. CONCLUSION: A baseline PC 0.12 in patients with CHTN and normal creatinine is associated with development of PE and PTB.
S186 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2016