High risks for adverse outcomes linked to COVID-19 with omicron variant at delivery

Key takeaways:

• Women with vs. without COVID-19 at delivery had significantly higher prevalence of adverse maternal and pregnancy outcomes.
• Increased risks were observed for sepsis, shock, stillbirth, preterm birth and more.

Risks for adverse outcomes associated with COVID-19 at delivery stayed high during the omicron variant window, despite possible immunity from previous SARS-CoV-2 infection, vaccination or testing differences, researchers reported.

“If you are pregnant or planning pregnancy, it is important to stay up to date with COVID-19 vaccinations to reduce the risk of getting very sick and experiencing problems from COVID-19 and to protect the health of your baby,” Jeffrey Carlson, PhD, an epidemiologist at the CDC’s National Center on Birth Defects and Developmental Disabilities, told Healio. “Although studies have suggested less severe outcomes during omicron compared to prior variant periods, the risk of complications for pregnant women with COVID-19 remained elevated during the omicron period compared with pregnant women without COVID-19.”

Carlson and colleagues conducted a cross-sectional observational study assessing data from 2,990,973 U.S. women with delivery hospitalizations from the Premier Healthcare Database from February 2020 to August 2023. Researchers categorized February 2020 to June 2021 as the pre-delta period, July to December 2021 as the delta period and January 2022 to August 2023 as the omicron period. COVID-19 exposure was identified via diagnostic code during delivery hospitalization.

Overall, 1.9% of women in the study had COVID-19 at delivery hospital admission discharge. Of these, 20,031 women had COVID-19 at delivery during the pre-delta period, 10,534 during the delta period and 26,053 during the omicron period.

Compared with pregnant women without COVID-19, those with COVID-19 had significantly higher prevalence of adverse maternal and pregnancy outcomes during delivery across all variant periods, according to researchers.

Women with COVID-19 at delivery during the omicron period had significantly increased risks for maternal sepsis (0.4% vs. 0.1%; adjusted prevalence ratio = 3.32; 95% CI, 2.7-4.08), acute respiratory distress syndrome (0.6% vs. 0.1%; aPR = 6.19; 95% CI, 5.26-7.29), shock (0.2% vs. 0.1%; aPR = 2.14; 95% CI, 1.62-2.84), renal failure (0.5% vs. 0.2%; aPR = 2.08; 95% CI, 1.73-2.49), ICU admission (2.7% vs. 1.7%; aPR = 1.64; 95% CI, 1.52-1.77), mechanical ventilation (0.3% vs. 0.1%; aPR = 3.15; 95% CI, 2.52-3.93), in-hospital mortality (0.03% vs. 0.01%; aPR = 5; 95% CI, 2.3-10.9), stillbirth (0.7% vs. 0.6%; aPR = 1.17; 95% CI, 1.01-1.36) and preterm delivery (12.3% vs. 9.6%; aPR = 1.28; 95% CI, 1.24-1.33) in adjusted models compared with women without COVID-19.

“These data only included COVID-19 infections at delivery, so more information is needed about the potential impacts of COVID-19 infections earlier in pregnancy,” Carlson said. “These findings underscore the importance of continued surveillance, research and monitoring of maternal, pregnancy and infant outcomes as new variants emerge.”