COVID-19 in Pregnant and Nonpregnant Women of Reproductive Age, Early 2020

This page summarizes a CDC analysis from the first months of the COVID-19 pandemic, covering cases reported from January 22 to June 7, 2020, and the advice given at the time.

Pregnancy brings changes in the immune system and body that could raise the risk of severe illness from respiratory infections. In mid-2020 there was little U.S. data on how COVID-19 affected pregnant women, so CDC compared women aged 15 to 44 with laboratory-confirmed SARS-CoV-2 infection by pregnancy status. As of June 16, 2020, the pandemic had caused 2,104,346 cases and 116,140 deaths in the United States.

The data

Of 1,573,211 laboratory-confirmed cases reported to CDC between January 22 and June 7, 2020, 326,335 (20.7%) were in women aged 15–44. Pregnancy status was known for 91,412 of them (28.0%), and 8,207 (9.0%) of those were pregnant. Missing outcome data were counted as the outcome not having occurred, to avoid overstating risk.

Who was infected

• Age: 54.4% of the pregnant women were aged 25–34 and 22.1% were 35–44, compared with 38.2% and 38.3% of nonpregnant women.
• Race and ethnicity (where known): among pregnant women, 46.2% were Hispanic, 23.0% non-Hispanic White, 22.1% non-Hispanic Black and 3.8% non-Hispanic Asian. Among women who gave birth in 2019, 24% were Hispanic, 15% Black and 51% White, suggesting Hispanic and Black pregnant women may have been disproportionately affected.
• Chronic conditions (where known): chronic lung disease (21.8% vs 10.3%), diabetes (15.3% vs 6.4%) and cardiovascular disease (14.0% vs 7.1%) were more common among pregnant than nonpregnant women. The data could not separate conditions that began before pregnancy from those related to it, such as gestational diabetes.

Symptoms

Almost all women with a known symptom status had symptoms (97.1% of pregnant and 96.9% of nonpregnant women). Cough (51.8% vs 53.7%) and shortness of breath (30.1% vs 30.3%) were about equally common, but pregnant women less often reported headache (40.6% vs 52.2%), muscle aches (38.1% vs 47.2%), fever (34.3% vs 42.1%), chills (28.5% vs 35.6%) and diarrhea (14.3% vs 23.1%).

Severity

Risk ratios were adjusted for age, underlying conditions and race and ethnicity. The hospitalization figure is hard to interpret, because the data could not distinguish admission for COVID-19 from admission for pregnancy care such as delivery, and some hospitals tested every woman admitted to labor and delivery. Intensive care and ventilation, though, are distinct signs of severe illness, and both were more likely in pregnancy. Among pregnant women, non-Hispanic Asian women were admitted to intensive care most often (3.5%). For all women, every severe outcome was more common at ages 35–44 than at 15–24.

A Swedish study had similarly found pregnant women with COVID-19 more likely to need intensive care and ventilation. With influenza, by comparison, a meta-analysis found pregnancy linked to a sevenfold higher risk of hospitalization but lower intensive care risk and no higher risk of death.

Why pregnant women made up 9%

About 5% of women aged 15–44 are pregnant at any given time, so 9% was higher than expected. That could reflect greater risk, but also missing pregnancy data among nonpregnant women, more frequent health care visits and testing during pregnancy, and universal testing policies at some obstetric units.

Advice at the time

The authors concluded that pregnant women might be at higher risk of severe COVID-19 and should be made aware of it. They advised pregnant women not to skip prenatal appointments, to limit contact with other people as much as possible, to take precautions when they did interact with others, to keep at least a 30-day supply of medicines, and to talk with their health care providers about staying healthy. CDC also began dedicated surveillance of pregnancy outcomes among women with COVID-19.

Limitations

• Pregnancy status was missing for about three-quarters of women, and other details were often missing too.
• Outcomes such as intensive care, ventilation and death may not yet have been reported.
• The data did not include trimester, or whether hospitalization was for COVID-19 or for pregnancy.
• Routine case surveillance does not capture pregnancy outcomes such as pregnancy loss or preterm birth.

Sources

• Sascha Ellington, Penelope Strid, Van T. Tong, Kate Woodworth, Romeo R. Galang, Laura D. Zambrano, John Nahabedian, Kayla Anderson and Suzanne M. Gilboa, "Characteristics of Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status — United States, January 22–June 7, 2020," Morbidity and Mortality Weekly Report, CDC: https://www.cdc.gov/mmwr/volumes/69/wr/mm6925a1.htm