Pregnant women with Covid-19 may be at increased risk of preterm delivery, CDC study suggests

Pregnant women with Covid-19 who are hospitalized may be at an increased risk of giving birth prematurely, a new study from the US Centers for Disease Control and Prevention suggests.

Data showed that 12.6% of live births among hospitalized women with Covid-19 in the study were preterm compared with 10% of births that were observed in the general US population in 2018.

“In this study, preterm births occurred approximately three times more frequently in symptomatic pregnant women than in those who were asymptomatic,” the CDC researchers wrote in the study.

The study, published on Wednesday, included data on 598 hospitalized pregnant women with Covid-19 in 13 states across the US between March 1 and August 22. More than half of the women, 54.5%, were asymptomatic when they were admitted to the hospital, the data showed.

Among the women who were showing symptoms, 16.2% ended up in the intensive care unit, 8.5% required invasive mechanical ventilation and two women, or 0.7%, died. No asymptomatic women needed intensive care, required mechanical ventilation or died, the study noted.

Pregnancy losses occurred for 2% of all pregnancies that were completed while in the hospital and were experienced by both symptomatic and asymptomatic women, the data showed.

Among the pregnancies that resulted in live births, preterm delivery was reported for 23.1% of symptomatic women compared with 8% of asymptomatic women, the data showed. Among the live births, two newborns died while in the hospital — both were born to symptomatic women who required invasive mechanical ventilation.

The study had some limitations, including that the data were only on pregnant women who were hospitalized and the reason for being hospitalized was unavailable for nearly half of the women in the data — which limits the ability to distinguish between who was hospitalized for pregnancy reasons versus reasons related to Covid-19.

“Pregnant women and health care providers should be aware of potential risks for severe COVID-19, including adverse pregnancy outcomes,” the researchers wrote.

This isn’t the first time that an association between preterm birth and Covid-19 has been identified.

A paper published earlier this month in the BMJ medical journal found pregnant women with Covid-19 were at increased risk of delivering preterm, but preterm birth rates were not high.

“While overall risks to pregnant women from coronavirus are low, the findings of this study highlight the particular risks to pregnant women,” Dr. Edward Morris, president of the Royal College of Obstetricians and Gynecologists, said in a statement at the time. “Pregnant women are included in the list of people at moderate risk as a precaution and pregnant women should therefore continue to follow the latest government guidance on social distancing and avoiding anyone with symptoms suggestive of coronavirus.”