COVID-19 Risks Among Pregnant Women Increase During Delta Surge

Pregnant women are at an increased risk of severe illness and death from COVID-19, a recent study in Mississippi confirmed, and investigators urged vaccinations for pregnant women.

The study by the Mississippi State Department of Health, detailed in the US Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report, describes 15 deaths associated with COVID-19 among women in Mississippi from March 1, 2020, to Oct. 6, 2021. A total of 1637 SARS-CoV-2 infections were reported among pregnant women during the study period.

“Pregnant women are at risk for severe illness and death as a result of COVID-19 infection,” Paul Byers, MD, state epidemiologist at the Mississippi State Department of Health told Contagion. “All the COVID-associated deaths in our study were not fully vaccinated against COVID-19.”

Byers said he was surprised by the rapid increase in COVID-19 associated deaths in pregnant women with the Delta surge. Six COVID-19-associated deaths were reported before the emergence of the Delta variant, representing five deaths per 1000 SARS-CoV-2 infections during pregnancy. The rate jumped during the time the Delta variant was the predominant variant (July 2021-October 2021), when nine COVID-19 associated deaths were reported, amounting to 25 deaths per 1000 SARS-CoV-2 infections during pregnancy.

“Vaccination is the key,” Byers said. “We want to ensure that clinicians providing care to pregnant women, or women planning to become pregnant, vaccinate their patients.”

None of the women who died were fully vaccinated. Only one had been partially vaccinated, and 5 deaths were reported before vaccinations became available.

“All women who are pregnant, recently pregnant, trying to become pregnant or might become pregnant in the future, should get vaccinated as soon as possible to prevent serious illness, death, and adverse pregnancy outcomes from COVID-19,” Byers said.

The median age of those who died was 30, 9 were Black, 3 were White and 3 were Hispanic. All were admitted to an ICU and 14 required mechanical ventilation. Emergency cesarean delivery was performed among seven. Three died during pregnancy, and 12 died after live birth. Among those who died after birth, the median time was 5 days postpartum. Fourteen of the women had underlying medical conditions.

Limitations to identifying pregnancy from death certificates and COVID-19 case reporting systems likely led to an underreported number of COVID-19 cases during pregnancy, the authors noted. Subsequently, ratios of deaths per 1000 may have been overestimated. Limitations of the study also included the small number of deaths and the absence of an in-depth review of whether the death was related to pregnancy.

The study is consistent with other research that has highlighted the risks of COVID-19 during pregnancy.

A recent study in Mexico found that maternal mortality in Mexico increased by 60% from February 2020 to February 2021, reversing a trend of decreased maternal mortality during the previous two years.

COVID-19 infection also has been associated with an increased risk of preterm labor. A study by University of California investigators found that the risk of preterm birth before 32 of gestation was 60% higher among women with COVID-19 compared from July 2020 to January 2021.

In August, the CDC updated their guidance to recommend COVID-19 vaccination for all women who are pregnant, recently pregnant and planning to become pregnant.