Delivery during hospitalization for COVID-19 more likely with non-omicron variants

Pregnant patients with COVID-19 who were hospitalized for symptomatic disease were more likely to deliver during their stay if they were admitted to the hospital during non-omicron pandemic waves, data showed.

Specifically, the rate of delivery during hospitalization for symptomatic disease — which the researchers termed “delivery for COVID-19” — was highest in patients who delivered during the delta wave.

Additionally, the findings — which were presented at the Infectious Diseases Society for Obstetrics and Gynecology Annual Meeting — supported existing research on the rate of adverse pregnancy outcomes and the effect of vaccination in pregnant people.

“Patients with COVID-19 diagnosed in pregnancy, specifically during the delta wave, had higher rates of adverse pregnancy complications when compared to other strains,” Amanda Craig, MD, a maternal-fetal medicine fellow at Duke University School of Medicine, told Healio. “More importantly, COVID-19 vaccination was protective against delivery for COVID-19.”

Craig and colleagues retrospectively reviewed the electronic medical records of 451 patients with COVID-19 who delivered in the Duke University Health System between March 2020 and Feb. 25, 2022. They assessed the rate of delivery for COVID-19, preterm birth, hypertensive disorders of pregnancy and cesarean delivery in each wave of the pandemic.

In total, 133 (25.3%) patients delivered during the wild-type wave between March and September 2020, 99 (18.8%) delivered during the alpha wave between November 2020 and March 2021, 62 (11.8%) delivered during the delta wave between August and October 2021 and 157 (29.8%) delivered during the omicron wave from December 2021 to February 2022.

Eleven patients had a delivery for COVID-19, all of whom were symptomatic and unvaccinated. There were significant differences between waves, with the greatest number of patients who delivered for COVID-19 doing so during the delta wave (n = 5). Notably, the odds of delivery for COVID-19 were 13 times higher in the delta vs. omicron wave.

There were also significant differences between waves for hypertensive disorders of pregnancy, with patients who delivered in the delta wave being twice as likely to have these disorders as those who delivered in the omicron wave.

Preterm birth was common (18.8%) across the cohort and did not vary by wave. Cesarean delivery also did not vary across waves.

“Our findings support initiatives focused on the importance of counseling patients considering pregnancy or currently pregnant about COVID-19 vaccination, particularly as we expect future COVID-19 variants with unknown virulence,” Craig told Healio. “Next steps include looking into duration of protection of COVID-19 vaccines and vaccine boosters during pregnancy, and potential timing for additional boosters in pregnancy.”