COVID-19 Vaccines During Pregnancy and Birth Defects; Preliminary Data from V-Safe COVID-19 Vaccine Pregnancy Registry, United States 2021

Background: Pregnant people are at increased risk for severe illness and complications from COVID-19. In the US, COVID-19 vaccination is recommended for pregnant people. There are limited data on the occurrence of birth defects after COVID-19 vaccination during pregnancy.

Objectives: Describe birth defects among pregnancies of people who received a COVID-19 vaccine during pregnancy.

Methods: V-safe is an active smartphone-based safety surveillance monitoring system developed by CDC to monitor the safety of COVID-19 vaccines. All participants reporting a pregnancy between December 2020 and May 2021 were invited to participate in the v-safe COVID-19 Vaccine Pregnancy Registry phone interview. Vaccination information was entered into v-safe by participants and confirmed during the interview. Participants were asked whether their fetus or infant was diagnosed with any birth defects or medical conditions; clinicians reviewed the participants' verbatim responses. Analyses described participant demographics, reported birth defects, and compared the rate of birth defects among participants receiving at least one mRNA vaccination in the month before pregnancy or the 1st trimester to those receiving an mRNA vaccination after 20 weeks' gestation.

Results: While interviews are ongoing, 11,105 participants completed the pregnancy outcome survey by January 10, 2022. We excluded 495 participants with either a miscarriage, ectopic, or tubal pregnancy, 211 participants with a multiple gestation pregnancy, and 388 participants reporting COVID-19 infection during pregnancy leaving 10,011 participants. Vaccine types included Pfizer-BioNTech (55%), Moderna (40%) and Johnson & Johnson's Janssen (5%). The mean participant age was 32.9 years, and two-thirds of participants were health care workers. Major birth defects were reported for 331 fetuses and infants, and in 3.7%, 2.9%, and 3.6% of the fetuses and infants of those receiving their first eligible vaccine dose in the 1st, 2nd, or 3rd trimester, respectively; specific birth defect review is ongoing.

Conclusions: mRNA COVID-19 vaccination in early pregnancy was not associated with an overall increase of birth defects in this convenient cohort of mostly health-care workers. This is the first report of birth defects from a U.S. COVID-19 vaccine pregnancy registry. These findings contribute to the growing evidence of safety of COVID-19 vaccination during pregnancy, which may reassure pregnant people and allow healthcare providers to better counsel patients.