(585) Risk for Stillbirth Following Maternal COVID-19 in Otherwise Low Risk Pregnancies

Current ACOG guidelines recommend consideration of third trimester antenatal surveillance in conditions with an increased risk for stillbirth. This study aims to evaluate whether antenatal COVID-19 during pregnancy increases risk for stillbirth in an otherwise low risk population.

Study Design:

This is a retrospective cohort study of pregnant patients without comorbidities who delivered after 20 weeks gestation between January 1 and December 31, 2021 in a large regional health system. Patients with higher order multiples, congenital anomalies and prior COVID vaccination were excluded, as were those with indication for antepartum fetal surveillance, including chronic hypertension, diabetes, age >40 years and body mass index >40. Antenatal COVID-19 during alpha and delta predominance diagnosed prior to delivery admission was the exposure of interest. Primary outcome was stillbirth. Secondary outcomes included small for gestational age (SGA), preterm delivery, neonatal intensive care unit (NICU) admission, and preeclampsia. Baseline characteristics were compared by Student’s T test, χ² test or Fischer exact test. Odds ratios were determined via logistic regression. P< 0.05 was considered statistically significant.

Results:

Of 11,413 deliveries included, 505 (4%) had COVID-19 during pregnancy. Non-smoking status and asthma were more common in those with COVID-19 (Table 1). Risk of stillbirth was not increased for those with history of COVID-19 (1.0% vs 0.5%, aOR 2.71, 95% CI 0.6 – 12.2, Table 2). Antenatal COVID-19 during pregnancy was associated with decreased risk for preterm delivery (11% vs 12%, aOR 0.4, 95% CI 0.2 – 0.8). SGA, NICU admission and preeclampsia were similar.

Conclusion:

In a large retrospective cohort of healthy pregnant patients otherwise at low risk for fetal death, COVID-19 was not associated with increased risk for stillbirth. A non-significantly increased risk justifies larger studies to determine a more precise point estimate to evaluate need for antepartum fetal surveillance.