COVID-19 mRNA Vaccines During Pregnancy: New Evidence to Help Address Vaccine Hesitancy
SARS-CoV-2 infection during pregnancy is associated with increased risk for maternal morbidity and adverse birth outcomes. COVID-19 vaccines are effective for preventing severe disease, including in pregnant populations. Although more than 100 countries recommend COVID-19 vaccination during pregnancy, COVID-19 vaccination in pregnant people has lagged behind that for age-matched, non-pregnant adults. As of February 2022, the US Vaccine Safety Datalink estimated that 68% of pregnant individuals have completed the primary COVID-19 vaccine series. Persistent wide disparities in COVID-19 vaccination during pregnancy by race or ethnicity are likely to exacerbate longstanding disparities in maternal morbidity and mortality.
Vaccine hesitancy during pregnancy was understandable when COVID-19 vaccines were first authorized, because pregnant people were excluded from the initial COVID-19 vaccine trials. Thus, initial data on pregnancy or birth outcomes after maternal COVID-19 vaccination were limited to inadvertent exposures among trial participants early in pregnancy. The mRNA vaccines were novel and their safety in pregnancy was presumed, but not yet proven. Over the past 14 months, a substantial body of evidence supporting the safety of the mRNA COVID-19 vaccines in pregnancy has accumulated. Observational studies from Norway, Israel, and the US have reported that the mRNA COVID-19 vaccines administered during pregnancy were not associated with increased risk for miscarriage, preterm birth, or other select obstetric and birth outcomes.
In this issue of JAMA, 2 population-based observational retrospective studies evaluating outcomes in more than 250 000 pregnancies from 3 countries together provide the strongest evidence to date regarding the safety of COVID-19 vaccines in pregnancy.