Pregnant women with COVID-19 had a higher risk of complications and death than those who did not contract the virus, adding further evidence to the increased risks the virus poses during pregnancy, according to a new study.
The global study, published Thursday in JAMA Pediatrics, found that pregnant women who contracted COVID-19 were 22 times more likely to die than pregnant women who did not contract the virus. They also were found to have an increased risk of severe pregnancy complications, including preeclampsia, preterm birth and intensive care unit admission. Individuals who were symptomatic or had comorbidities, such as diabetes or were overweight, had a greater risk of complications and death, researchers said.
Pregnant women who had asymptomatic infections had a higher risk for preeclampsia, though otherwise had similar outcomes to pregnant women who were not diagnosed with COVID-19, researchers said.
Newborns of the women diagnosed with COVID-19 were more likely to be born preterm and have severe complications, including NICU stays of seven days or longer, the study found.
"The findings should alert pregnant individuals and clinicians to implement strictly all the recommended COVID-19 preventive measures," the authors said.
Doctors from the University of Washington School of Medicine and the University of Oxford led the research. The study enrolled 2,130 pregnant women from 43 maternity hospitals in 18 countries and was conducted from April to October of 2020.
"I would highly recommend that all pregnant women receive the COVID-19 vaccines," Dr. Michael Gravett, a professor of obstetrics and gynecology at the UW Medicine and one of the study's lead authors, said in a statement.
There is limited data on the safety of COVID-19 vaccines in pregnant people. A study published in the American Journal of Obstetrics & Gynecology in March found the Pfizer and Moderna vaccines are safe and effective in pregnant and lactating people.
The U.S. Centers for Disease Control and Prevention advises that pregnant people "might choose to be vaccinated." Pregnancy is classified as a high-risk medical condition by the CDC, which notes that "although the overall risk of severe illness is low, pregnant people are at an increased risk for severe illness from COVID-19 when compared to non-pregnant people."
The World Health Organization recommends that pregnant women at high risk of exposure to COVID-19 or who have comorbidities that would increase their risk of severe disease get vaccinated in consultation with their health care provider.
The UW Medicine and University of Oxford study enrolled 706 women with a COVID-19 diagnosis. Each woman diagnosed with COVID-19 was compared to two uninfected pregnant women who gave birth at the same hospital around the same time, according to UW Medicine.
Among the women diagnosed with COVID-19, 13% of infants tested positive for COVID-19 at birth. Cesarean delivery increased the risk for a positive COVID-19 test in infants, though breastfeeding did not, researchers found.
Shortness of breath, chest pain and cough with fever were associated with a "substantial" increase in the risk of complications for the mother and preterm birth, the study found.
Under 2% of those enrolled in the study who had a COVID-19 diagnosis died. Of those 11 women, four had severe preeclampsia, five had respiratory failure before the birth, and two died within a week of delivery after being admitted to the ICU. One woman who did not have a COVID-19 diagnosis died due to preexisting liver cancer and cirrhosis.
The study mostly included women in their third trimester. Further research of the effect of COVID-19 earlier in pregnancy "needs urgently to be studied," the study's authors said.