619: A history of prior preeclampsia is a major risk factor for preterm birth

major risk factor for preterm birth Brendan Connealy, Carlos Carreno, Benjamin Kase, Laura Hart, Sean Blackwell, Baha Sibai University of Texas Health Science Center Houston, Obstetrics, Gynecology, and Reproductive Sciences, Houtson, TX OBJECTIVE: Women with prior preeclampsia are considered at increased risk for adverse pregnancy outcomes (recurrent preeclampsia, fetal growth restriction, abruptio placentae). Limited data exists to describe an association between prior preeclampsia and spontaneous preterm birth (SPTB). Our objective is to evaluate the frequency of SPTB in women with prior preeclampsia and describe neonatal outcomes in these infants compared those with indicated preterm birth (IPTB). STUDY DESIGN: This is a secondary analysis of data in women with prior preeclampsia enrolled in a multicenter randomized trial of low dose aspirin for preeclampsia prevention. Inclusion criteria were women with history of prior preeclampsia, and live fetus. Women with preexisting medical disorders were excluded. Indications for delivery were categorized as SPTB (PTL or PPROM) and IPTB. Primary outcomes were rates of SPTB and IPTB by GA. Composite respiratory morbidity and NICU admission were compared between groups. Chi square and t test were used to establish a difference between the study groups. RESULTS: Of the 606 pregnancies studied, 142 (23%) delivered at 37 weeks. Of those delivered preterm, 47% were due to SPTB and 53% were IPTB. The table below summarizes the frequency of PTB by subtype and GA. There were no significant differences in rates of SPTB or IPTB, or in the rates of composite neonatal morbidity, between the GA groups. There were 14 perinatal deaths (2.3%): of which the majority (13) were at 34 weeks. Additionally, there were no differences in NICU admission between the groups. CONCLUSION: Women with prior preeclampsia have a substantially high rate of preterm birth with almost half being spontaneous and nearly two-thirds occurring in the late preterm. We recommend that prior preeclampsia should be considered a risk factor for both IPTB and SPTB with the potential for early intervention to improve perinatal outcome. 620 Timing of adverse neonatal outcomes in pregnancies complicated by preeclampsia and small for gestational age births in a cohort of high-risk pregnancies Cande Ananth, Jaclyn Coletta-Lucas, Ronald Wapner Columbia University Medical Center, Department of Obstetrics and Gynecology, New York, NY OBJECTIVE: In a group of high-risk women with underlying medical conditions predisposing to preeclampsia and small for gestational age (SGA), the timing of delivery is often based on a worsening maternal condition. We evaluated the risk of adverse neonatal outcomes in early intervention compared to spontaneous delivery. STUDY DESIGN: We performed a secondary analysis of data from the Maternal-Fetal Medicine Units network of a randomized controlled trial of aspirin to prevent preeclampsia in high-risk women (those with chronic hypertension, insulin-dependent diabetes mellitus and women with previous preeclampsia). The trial resulted in no benefit of aspirin on the risk of preeclampsia. We examined risks of adverse composite neonatal outcomes (perinatal death, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, retinopathy of prematurity, patent ductus arteriosus, pulmonary hypertension, neonatal seizures, admission to the neonatal intensive care unit and 5-minute Apgar 5) in relation to preeclampsia and small for gestational age (SGA, birthweight 10% for gestational age). Odds ratio (OR) and 95% confidence interval (CI) were estimated from logistic regression models after adjusting for potential confounders. RESULTS: Of the 1,787 women in the high-risk trial, the overall risk of composite neonatal outcome was 29.3%. The risk of composite outcome was higher in the SGA-only and preeclampsia (with or without SGA) groups, but this association was evident only at preterm gestations (Table). Among infants that were SGA (only), the risk of neonatal morbidity was dramatically higher among women that had a spontaneous rather than indicated preterm birth. CONCLUSION: In a group of women at high-risk for preeclampsia, appropriately timed obstetrical interventions at preterm gestations, relative to spontaneous preterm birth, is associated with reduced risk of neonatal morbidity.