A study by Boston University researchers finds that COVID-19 vaccines do not increase the risk of miscarriage in people planning a pregnancy. This reassuring evidence supports the safety of preconception vaccination and is consistent with health officials' recommendations for vaccination in those planning to become pregnant.
The new study, the first to prospectively assess the relationship between COVID-19 vaccination and miscarriage in both partners before pregnancy, found that the risk of miscarriage was slightly reduced in couples who were vaccinated and trying to conceive.
Numerous studies show that COVID-19 vaccines do not cause infertility or increase the risk of pregnancy-related problems, including miscarriage. Despite this evidence, people remain wary of the potential negative effects of vaccines on pregnancy.
A recent study by researchers at Boston University School of Public Health (BUSPH) provides more comprehensive information about the safety of COVID-19 vaccines for people considering pregnancy.
The study, published in the journal Human Reproduction, found that having a male or female partner vaccinated against COVID-19 before pregnancy did not increase the risk of early or late miscarriage.
Implications from new research on pre-pregnancy vaccine safety
The study is the first to assess the risk of early miscarriage (less than 8 weeks gestation) after COVID-19 vaccination before pregnancy, and the first to assess the relationship between vaccination and miscarriage in men. The researchers hope the results will provide useful information to individuals planning a pregnancy and their health care providers.
"These findings should be replicated in other populations, but they are reassuring for couples planning a pregnancy," said study first author Jennifer Yland, a doctoral student in epidemiology at the Bush Institute of Health.
In the study, Yland and colleagues analyzed survey data on COVID-19 vaccination and miscarriage among female and male participants in the BUSPH-based Pregnancy Study Online (PRESTO), an ongoing study funded by the National Institutes of Health. Participants in the new analysis included 1,815 women in the United States and Canada who were followed between December 2020 and November 2022. They are monitored from the time of their first positive pregnancy test until miscarriage or other events (such as induced abortion, ectopic pregnancy, or 20 weeks' gestation), whichever occurs first.
Among female participants, 75% had received at least one dose of a COVID-19 vaccine before becoming pregnant. Nearly a quarter of pregnant women miscarry, and 75% of these miscarriages occur before 8 weeks of pregnancy, but there is no increased risk.
The risk of miscarriage was 26.6% among unvaccinated women; 23.9% among women who had received one dose before conception; 24.5% among women who completed the entire primary vaccine series before conception; 22.1% among women who completed the vaccine series three months before conception; and 20.1% among women who had received only one of two doses before conception.
"Not only were the miscarriage rates among vaccinated people comparable to PRESTO participants who conceived before the pandemic, but our data suggest that the risk of miscarriage among vaccinated people was slightly lower than among nonvaccinated people," Yland said.
Federal health officials continue to recommend that people planning to become pregnant get vaccinated against COVID-19, emphasizing that the benefits of getting vaccinated against COVID-19 outweigh the potential risks of getting vaccinated before or during pregnancy.
References "A prospective cohort study of preconception COVID-19 vaccination and miscarriage" by Jennifer JYland, Amelia KWesselink, Annette KRegan, Elizabeth EHatch, Kenneth JRothman, David ASavitz, TanranRWang, KristaFHuybrechts, Sonia Hernández-Díaz, Michael LEisenberg, and Lauren AWise, October 20, 2023, Human Reproduction.
DOI:10.1093/humrep/dead211
Compiled source: ScitechDaily