In an urgent plea on Wednesday, federal health officials asked that any American who is pregnant, planning to become pregnant or currently breastfeeding get vaccinated against the coronavirus as soon as possible.
Covid-19 poses a severe risk during pregnancy, when an individual’s immune system is tamped down, and raises the risk of stillbirth or another poor outcome, according to the Centers for Disease Control and Prevention. Twenty-two pregnant individuals in the United States died of Covid in August, the highest number in a single month since the pandemic started.
Some 125,000 pregnant people have tested positive for the virus; 22,000 of them have been hospitalized, and 161 have died. Hospital data indicates that 97 percent of those who were infected with the virus when they were hospitalized — for illness, or for labor and delivery — were not vaccinated.
Vaccination rates among those who are pregnant are lower than among the general population. Fewer than one-third of all pregnant people were vaccinated before or during their pregnancy, the agency said.
The rates vary widely by race and ethnicity, with the highest — nearly 50 percent — among pregnant Asian American individuals, and the lowest rates among pregnant Black individuals, at just 15 percent.
Pregnancy is on the C.D.C.’s list of health conditions that increase the risk of severe Covid. Though the absolute risk of severe disease is low, pregnant patients who are symptomatic are more than twice as likely as other symptomatic patients to require admission to intensive care or interventions like mechanical ventilation, and may be more likely to die.
Some data also suggest that pregnant individuals with Covid-19 are more likely to experience conditions that complicate pregnancy — like a kind of high blood pressure called pre-eclampsia — compared with pregnant individuals who don’t have Covid. Pregnant individuals with the disease are also at increased risk for poor birth outcomes, like preterm birth.
Clinical trials have a long history of excluding those who are pregnant from participation, and pregnant individuals were not included in the coronavirus vaccine trials. As a result, data on the safety and effectiveness of vaccines is limited in this group.
Studies conducted since the vaccines were authorized, however, have shown that the vaccines do not increase the risk of a miscarriage. Both the Pfizer-BioNTech and Moderna vaccines produced robust immune responses in those who are pregnant, and did not damage the placenta, researchers have found.
“Pregnancy can be both a special time and also a stressful time, and pregnancy during a pandemic is an added concern for family,” said Dr. Rochelle Walensky, the director of the C.D.C. She encouraged those who are pregnant and those who may become pregnant “to talk with their health care provider about the protective benefits of the Covid-19 vaccine to keep their babies and themselves safe.”