634: Maternal and neonatal outcomes of placenta accreta stratified by gestational age at delivery

To evaluate maternal and neonatal outcomes in cases of placenta accreta delivered at different gestational ages. We performed a retrospective cohort study of all cases of placenta accreta from 2009 to 2014 delivered at the five academic hospitals comprising the University of California Fetal Consortium (UCfC). Demographic characteristics and outcomes were collected by chart review. The patient cohorts delivered at <34 weeks, 34 weeks, 35 weeks, and ≥36 weeks were compared in respect to maternal and neonatal outcomes. ANOVA or Kruskal-Wallis tests were used for continuous variables and chi-squared analyses for categorical variables. Of 161 cases identified in the study period, 155 (96%) had pathologic evidence of morbidly adherent placenta. 56 (36%) were delivered <34 weeks, 41 (27%) in the 34th week, 23 (15%) in the 35th week, and 35 (23%) at ≥36 weeks. Demographic characteristics were similar between groups (Table). Prenatal diagnosis of accreta was more common in the groups delivered <36 weeks (p<0.01). In those prenatally diagnosed with accreta, diagnosis occurred at earlier gestational ages in the earlier delivery groups. Antepartum bleeding and unscheduled delivery were more common in the <34 week group. Rates of antepartum bleeding ranged from 34-80% over the different gestational age groups. There were no differences in the rates of intraoperative or postoperative transfusion, quantities of administered PRBCs, or urinary tract or bowel injury between gestational age groups. Operative time and estimated blood loss were also similar between groups. The median postpartum length of stay was 1 day longer in the <34 week group, however all groups had a median of 4-5 days. Adverse neonatal outcomes including birth weight <2500 grams, respiratory distress syndrome, and surfactant use occurred more often in the earlier delivery groups as expected. In this large contemporary cohort, the rate of maternal operative complications and transfusion requirements were not affected by gestational age at delivery. However, the persistent high risk in all gestational age groups for antepartum bleeding likely warrants planned preterm delivery.