A paper published in PLOS One finds that maternal COVID-19 infection during delivery increases the risk of poor maternal and fetal outcomes, with the most severe effects noted during the Delta variant wave early in the pandemic.  

“Overall, this study demonstrates that obstetric risk associated with COVID-19 was not static but evolved across variant periods, highlighting the need for ongoing maternal health surveillance and adaptive healthcare policies as infectious disease patterns change,” wrote the authors, led by researchers from the US Department of Health and Human Services. 

“These findings provide a framework for assessing and responding to variant-driven shifts in pregnancy risk during future infectious disease outbreaks,” they added.

Confirms previous research findings

The retrospective cohort study of nearly 2.6 million hospital delivery discharges—which included 53,226 moms (2.1%) diagnosed as having COVID-19—examined maternal and fetal outcomes across the pre-Alpha, Alpha, Delta, and first Omicron waves, from April 1, 2020, to March 31, 2023. 

Likewise, previous studies have observed an elevated risk of preterm birth associated with COVID-19 infection This study corroborates these findings.

Having COVID-19 at delivery was associated with an increased risk of fetal death at 20 weeks or later during the pre-Alpha and Delta waves of COVID-19. Throughout the pandemic, COVID-19 infection at delivery was linked to a greater chance of maternal intensive care unit admission and preterm birth. Cesarean birth rates increased throughout the pandemic, except during the Alpha and the first Omicron waves. 

“The markedly elevated risk of fetal death is consistent with prior research observing elevated preterm delivery risk across variant periods, most notably during the early stages of the pandemic,” the authors wrote. “Likewise, previous studies have observed an elevated risk of preterm birth associated with COVID-19 infection This study corroborates these findings.”