COVID-19-related Health Outcomes during Delivery Hospitalization During Pre-delta, Delta, and Omicron Periods

Abstract Background SARS-CoV-2 infection during pregnancy has been associated with several adverse maternal health and pregnancy outcomes; however, few studies have included pregnancies occurring during the time period of Omicron variant predominance (January 2022–present) in the evaluation of pregnancy outcomes. We examined the relationship between COVID-19 diagnosis at delivery and adverse maternal and pregnancy outcomes for each variant period, with a focus on Omicron. Methods Data on delivery hospitalizations from the Premier Healthcare Database during February 2020 –August 2023 were analyzed as a cross-sectional observational study. Adjusted prevalence ratios (aPR) were calculated to compare the risks of adverse outcomes between women with and without a COVID-19 diagnosis at the time of delivery for each variant period. Results Among 2,990,973 women with a delivery hospitalization, 1.9% (n = 56,618) had a COVID-19 diagnosis noted on discharge, including 26,053 during the Omicron period. In adjusted models, COVID-19 during the Omicron period was associated with a significant increased risk for maternal sepsis (COVID-19: 0.4% vs No COVID-19: 0.1%) (aPR: 3.32 [95%CI: 2.70, 4.08]), acute respiratory distress syndrome (0.6% vs 0.1%) (6.19 [5.26, 7.29]), shock (0.2% vs 0.1%) (2.14 [1.62, 2.84]), renal failure (0.5% vs 0.2%) (2.08 [1.73, 2.49]), ICU admission (2.7% vs 1.7%) (1.64 [1.53, 1.77]), mechanical ventilation (0.3% vs 0.1%) (3.15 [2.52, 3.93]), in-hospital death (0.0% vs 0.0%)(5.00 [2.30, 10.90]), stillbirth (0.7% vs 0.6%) (1.17 [1.01, 1.36]), and preterm birth (12.3% vs 9.6%) (1.34 [1.27, 1.42]). Conclusions During the Omicron variant period, risks of adverse outcomes associated with COVID-19 diagnosis at delivery remain elevated, despite the possibility of some level of immunity due to previous SARS-COV-2 infection or vaccination. It remains important for pregnant people, and those planning pregnancy, to stay up to date with COVID-19 vaccination to reduce the risk of adverse outcomes.