Amniocentesis compared with antenatal corticosteroids prior to early term scheduled cesarean delivery

Objective: There are a variety of maternal or fetal conditions that require late preterm or early term delivery. In cases where early delivery is indicated, optimal management is not always clear. Historically, obstetricians used amniocentesis to document fetal lung maturity, but recently, many have transitioned to administration of antenatal corticosteroids (ACS). The objective of this study was to compare neonatal outcomes between women undergoing amniocentesis or receiving ACS prior to scheduled cesarean delivery (CD) less than 39 weeks.

Methods: This was a retrospective cohort study of women undergoing scheduled CD by one maternal-fetal medicine practice between 36 and 38 6/7 weeks, from 2005 to 2017. We identified women who underwent amniocentesis or received ACS within 2 weeks prior to delivery. Neonatal outcomes were compared between the two groups, with the primary outcome being neonatal intensive care unit (NICU) admission.

Results: A total of 502 women were included, of whom 313 (62.4%) underwent amniocentesis and 189 (37.6%) received ACS. Overall, 55 (11.0%) of neonates were admitted to the NICU. NICU admission was not significantly different between groups (11.8 versus 9.5%, p=.46). This held true after adjusting for gestational age and other differences in baseline characteristics. There were no significant differences between groups for all other neonatal outcomes, including NICU admission for respiratory indications, respiratory support, neonatal greater than maternal length of stay, low Apgar scores, and neonatal death. Rates of hypoglycemia were low and not significantly different between groups (2.2% in the amniocentesis group versus 0.5% in the ACS group, p=.27). Diabetes was the only covariate significantly associated with NICU admission (aOR 3.19, 95% CI 1.35, 7.54).

Conclusions: In women undergoing scheduled CD between 36 and 38 6/7 weeks, administration of ACS is associated with similar neonatal outcomes compared to amniocentesis. This supports the current notion that outcomes are similar with ACS compared to amniocentesis for late preterm and early term deliveries.

Brief rationale: The objective of this study was to compare neonatal outcomes between women undergoing amniocentesis or receiving antenatal corticosteroids (ACS) prior to scheduled cesarean delivery (CD) less than 39 weeks. We found that in women undergoing scheduled cesarean delivery between 36 and 38 6/7 weeks, administration of antenatal corticosteroids is associated with similar neonatal outcomes compared to amniocentesis.