COVID-19 mortality rates higher in pregnant women than in similarly aged individuals

Reviewed by Emily Henderson, B.Sc.Jan 27 2021

Contracting COVID-19 while pregnant can have deadly consequences for the mother, a new study published today in American Journal of Obstetrics and Gynecology shows.

The study, which followed 240 pregnant women between March and June 2020, found that the COVID-19 mortality rate in the pregnant women was significantly higher when compared to the COVID-19 mortality rate in similarly aged individuals within Washington state.

Specifically the study found:

• Pregnant women with COVID-19 had 3.5 times higher COVID-19 associated hospitalization rate than the similarly aged general population in Washington state.
• COVID-19 mortality rates were 13 times higher in pregnant mothers than in similarly aged individuals. This said, most of the pregnant patients with COVID-19 had asymptomatic or mild COVID-19 disease and healthy pregnancies.
• The three women who died of COVID-19 in Washington state were from minority ethnic groups and most of them had other conditions such as obesity and hypertension.

Of the 240 pregnant women with SARS-CoV-2 infections detected through June, three died from COVID-19, while 24 patients were hospitalized for COVID-19. Dr. Kristina Adams Waldorf, an obstetrician-gynecologist with the University of Washington School of Medicine, and senior author of the study, noted that this shows a severe underreporting of mortality related to COVID among mothers in the United States.

"The mortality rate was shockingly high," Adams Waldorf said. "We were very surprised by this."

The three maternal deaths from the study cohort in Washington state represent 6.7% of all maternal deaths associated with COVID-19 counted in the entire United States through mid-October, although annual births at the collaborating sites make up only 1.4% of annual births nationally, she said.

"We are gravely concerned that COVID-19-associated maternal deaths have been massively undercounted nationally and that the impact on pregnant patients, particularly with underlying conditions is greater than currently underappreciated," she added. The date was compiled by aWashington state collaborative that included 35 large hospitals and clinic systems. They performed 61 percent of the 86,000 annual state deliveries. The Washington State COVID-19 in Pregnancy Collaborative was led by Dr. Adams Waldorf and Dr. Erica Lokken, an epidemiologist at the University of Washington.

The study made several comparisons between the clinical course of COVID-19 and Influenza A virus H1N1 2009.

Unlike the influenza A virus H1N1 2009 pandemic, when pregnant women were quickly identified in the United States as a high-risk and vulnerable group, pregnancy was not identified as a high-risk condition for COVID-19 disease or mortality for the first, critical eight months of the pandemic, the report noted.

Overall, the data in this study indicates that pregnant patients are at risk for severe or critical disease or mortality compared with non-pregnant adults, as well as for preterm birth, the report concludes.

"The idea that pregnant patients were protected from COVID-19 is a myth," said Adams Waldorf.

Use of this data in the report is important, Waldorf notes, because it can guide public health workers and physicians in their mitigation of COVID-19 among vulnerable populations. Pregnant health care workers are already receiving the COVID-19 vaccine. But as of Jan. 27, most pregnant individuals are not included in the groups that can receive vaccinations now.

"Our data indicates that pregnant people did not avoid the pandemic as we hoped that they would and communities of color bore the greatest burden," Waldorf said. She urges pregnant women to discuss the risks and benefits of COVID-19 vaccination with their prenatal care provider.

These results suggest that the exclusion of pregnant patients from COVID-19 vaccine trials was a mistake. Here is an important group that is typically highly vulnerable to influenza infections and, yet they were excluded from COVID-19 vaccine trials. Pregnant patients should have been given the option to enroll in vaccine trials so that we would better understand vaccine risks and benefits to them."

Dr. Kristina Adams Waldorf, Obstetrician-Gynecologist, University of Washington School of Medicine

Adams Waldorf added that although the community may be experiencing COVID-19 fatigue this is no time to let our collective guard down, especially with the new variants present within our communities.

"We still need to be really careful about how large our bubble is within our families, to be very careful about handwashing and mask use, and to do everything that we can until enough of the population is vaccinated that we have herd immunity in the U.S., " she said.