AAlthough placental transmission of SARS-CoV-2 is rare, pregnant people are at increased risk of severe COVID-19, which is why many experts and scientific societies have argued that vaccination is a must during pregnancy. However, initial clinical studies excluded pregnant people, so there are limited clinical data on this population.
The first large-scale results are now in, and they are encouraging. According to a study by scientists from the US Centers for Disease Control and Prevention in the New England Journal of Medicine Yesterday (April 21), neither the Moderna nor Pfizer / BioNTech COVID-19 vaccines currently approved for emergency use in the US are at increased risk of serious side effects or adverse pregnancy outcomes.
The study looked at self-reported symptoms of more than 35,000 people, ages 16 to 54, who were pregnant when they received their COVID-19 vaccination and who participated through a smartphone-based reporting system called v-safe. It also analyzed the results of mothers and newborns from nearly 3,600 participants who opted for an additional telephone registry to collect detailed information about their pregnancies.
Participants reported injection site pain slightly more often than v-Safe users who did not say they were pregnant, but less likely to experience fever, chills, or pain. Among the 827 birth outcomes available, the rates of pregnancy loss, preterm birth, and small size were “similar to studies of pregnant women conducted prior to the COVID-19 pandemic,” the authors write in their report.
Stephanie Gaw, a maternal-fetal medicine specialist at the University of California at San Francisco who did not participate in the study, said The New York Times that the results are “very reassuring” and “will really help public health providers and officials recommend the vaccine more strongly in pregnancy”.
“It’s great to have data for our patients,” Laura Riley, OB / GYN chairman of New York’s Weill Cornell Medicine, told the Associated Press.
The study has several limitations, and the authors noted that additional research is needed, especially for vaccinations that occur early in pregnancy. In addition to the dependency on self-reporting and the low number of pregnancies examined, the study only included vaccinations that took place between December and the end of February and were mostly given by healthcare workers and mostly included people in their second trimester or later.