New research led by Minnesota-based HealthPartners Institute found mRNA COVID vaccines were not linked to an increased risk of miscarriage.
The findings, published Wednesday in JAMA, fit with previously existing research that suggests the Pfizer and Moderna vaccines are safe for people who are pregnant, HealthPartners said in a news release.
Elyse Kharbanda, MD, senior investigator at HealthPartners Institute and lead author on the study, said this "growing body of research that should give pregnant people confidence to get vaccinated against COVID-19, if they haven’t already."
The research looked over data gathered from De. 15, 2020, through June 28, 2021, comprising 105,000 patients who were in the early part of their pregnancy (which is when miscarriages can occur, HealthPartners said).
They then looked at the proportion of miscarriages that occurred among those who had been vaccinated within the previous 28 days, and compared it to the proportion of miscarriages among unvaccinated individuals.
The rate for both groups was "nearly identical," HealthPartners said, adding: "This suggests that vaccines had no impact the miscarriages."
The impact of COVID vaccinations on pregnancy has been the subject of unfounded rumors online, with data often taken out of context or presented in a misleading manner.
The Medicines and Healthcare products Regulatory Agency in the UK is among those that have recently said there's "no evidence" the shots increase rates of miscarriage or impact fertility. The CDC in the U.S. announced similar findings around the same time, writing: "Miscarriage typically occurs in about 11-16% of pregnancies, and this study found miscarriage rates after receiving a COVID-19 vaccine were around 13%, similar to the expected rate of miscarriage in the general population."