301: The impact of mode of delivery on subsequent pregnancy outcomes after periviable birth

Abstract

A pregnancy at risk of delivery in the periviable period presents a clinical and ethical challenge, requiring in-depth counseling and complex decision-making. While it is generally known that cesarean delivery (CD) increases maternal morbidity compared to vaginal delivery (VD), there is limited information regarding the implications of periviable mode of delivery on subsequent pregnancy outcomes. Our study assesses whether women who undergo a periviable CD (index CD) have increased rates of severe maternal morbidity in subsequent pregnancies as compared to those with a prior periviable VD (index VD). This is a retrospective cohort study of all pregnant women who had live born deliveries between 22- 26 weeks gestation and a subsequent pregnancy during 2004-2016 at a single tertiary care center. Maternal and neonatal demographic information for both the index periviable and subsequent pregnancies were collected and analyzed using chi-square and t-test statistics. The primary outcome was a composite of severe maternal morbidity, including uterine complications, ICU admission, sepsis, venous thromboembolism and transfusion. Secondary maternal obstetric complications and neonatal morbidity parameters were also analyzed. Multivariable logistic regression modeling was performed to determine the impact of index mode of delivery on composite maternal and neonatal morbidity outcomes. One hundred and thirty-four women and 161 neonates met inclusion criteria. Maternal and neonatal demographics of the index VD (n=60) versus index CD (n=74) groups were similar. There was no statistically significant difference in the maternal morbidity composite in the unadjusted (OR 1.69, 95%CI 0.36 - 7.87) or adjusted models (aOR 0.25, 95%CI 0.02 - 3.85). There were no hysterectomies or maternal deaths in either group. Only one uterine rupture case was noted in the index CD group. Analyzed secondary maternal outcomes and subsequent neonatal outcomes were not significantly different between groups. In our cohort, women who undergo a periviable CD do not have higher odds of severe maternal morbidity in subsequent pregnancies when compared to those with a prior periviable VD. Pooled multi-institutional data is necessary to further define the lifetime maternal risks of periviable birth for use in patient counseling.