A study about women who contracted COVID-19 during pregnancy found that those with severe or critical COVID-19 to be at greater risk of dying and experiencing serious complications compared with asymptomatic women with COVID-19. The study was led by Torri Metz, MD, MS, a maternal-fetal medicine subspecialist and associate professor at University of Utah Health.
About the study
The study examined 1,219 pregnant women who tested positive for COVID-19 between March 1 and July 31, 2020, at 33 hospitals in 14 states in the U.S. 47 percent were asymptomatic, 27 percent were mild, 14 percent were moderate, 8 percent were severe, and 4 percent were critical. The study predominantly evaluated women with COVID-19 in their third trimesters. It's not known at this time whether outcomes for pregnant women who get infected with COVID-19 at the beginning of their pregnancy are different from those without infection.
- 12 percent of women were severely or critically ill.
- Women who had more severe disease were more likely to be older, obese, or have a higher BMI and were more likely to have underlying comorbidities (such as hypertension, liver disease, or have diabetes).
- Patients who had severe or critical illness were at risk for a number of adverse pregnancy outcomes, such as preterm birth, ICU admission, developing high blood pressure during pregnancy, and having a hemorrhage or bleeding after pregnancy.
- In the group with severe or critical illness:
- 60 percent had a cesarean delivery
- 50 percent of babies went to the NICU
- 42 percent had a preterm birth (less than 37 weeks)
- 40 percent developed high blood pressure during pregnancy
- Four women (0.3 percent, or 3 per 1,000) died due to COVID-19, a figure much higher than the death rate for pregnant women without COVID-19 in the U.S.
- Pregnant women who experienced a mild to moderately ill COVID-19 infection did not have an increased risk for adverse pregnancy outcomes.
Impact on newborns
The study found that one percent of babies born tested positive for COVID-19 during the delivery. "This doesn't necessarily mean that the virus is transmitted in utero but that the virus may have been transmitted shortly after delivery or during the delivery process," Metz says. There are currently no data yet on the long-term effects on babies if their moms have COVID-19 during pregnancy.
Race, region, and origin
Out of the 1,219 patients who participated in the study, 53 percent were Hispanic. "This is higher than we expected, but it is consistent with other data that people of color are disproportionately effected by COVID-19," Metz says. Although people of color are more likely to contract the virus, the study did not find a difference in disease severity by race.
COVID-19 vaccines and pregnancy
With this new research, there's now more information about COVID-19 pregnancy outcomes. Metz says it's also important to advocate for women to be included in trials from the start so that more safety data are available to this group. "The issue is people try to protect pregnant women from research," Metz says. "Ultimately, that does not benefit pregnant people or their babies."
Pregnant women should minimize exposure to COVID-19 by getting vaccinated, wearing a face mask, frequently washing their hands, physically distancing, and staying away from people who are sick. "It's important to understand there are risks associated with pregnancy at any time," Metz says. "If a woman contracts COVID-19, those risks are higher."
Patients should also weigh other medical comorbidities, as well. If patients have high blood pressure, diabetes, or are obese, then they are generally at higher risk of pregnancy complications.