After a brief, unexpected rise in births early in the COVID-19 pandemic, birth rates in the United States and other wealthy nations have since declined. This drop sparked speculation that the widespread rollout of mRNA COVID-19 vaccines might be a contributing factor, with concerns raised about potential impacts on fertility and pregnancy outcomes.
However, a recent study conducted in Sweden offers reassuring evidence against these claims. Researchers investigated whether COVID-19 vaccination was associated with changes in childbirth rates and miscarriage rates, analyzing data from nearly 60,000 women aged 18 to 45 in Region Jönköping County between 2021 and 2024. The findings, published in Communications Medicine, suggest that COVID-19 vaccines are highly unlikely to have a negative effect on fertility or childbirth rates.
Approximately 75% of the women included in the study received at least one dose of a COVID-19 vaccine during the study period, with 97% of those vaccinated receiving an mRNA vaccine. When researchers compared childbirth rates between vaccinated and unvaccinated women, they found no statistically significant difference. In fact, vaccinated women were 3% more likely to give birth, though this difference was not large enough to be considered statistically meaningful.
Similarly, the study found no significant association between vaccination status and miscarriage rates. Vaccinated women were 14% less likely to experience a miscarriage, but again, this difference was not statistically significant, meaning it could have occurred by chance.
“We see no difference in childbirth rates between those who have taken the vaccine and those who haven’t,” said Toomas Timpka, professor of social medicine at Linköping University and one of the study authors. “We’ve also looked at all registered miscarriages among those who became pregnant and we see no difference between the groups there either.”
These findings align with a growing body of research that has consistently shown no evidence of a link between COVID-19 vaccination and adverse reproductive outcomes. Previous large-scale studies and reviews, involving hundreds of thousands of pregnant women, have similarly found no increased risk of miscarriage or stillbirth associated with COVID-19 vaccination. The American College of Obstetricians and Gynecologists (ACOG) and other major medical organizations have also affirmed that research has not identified any impact of COVID vaccines on male or female fertility.
Dr. Viki Male, an associate professor in reproductive immunology at Imperial College London, who was not involved in the Swedish study, commented that the findings should “further reassure women that COVID vaccination will not prevent them from getting pregnant or having a baby.”
While the study effectively addresses concerns about a direct link between vaccination and reduced fertility, it’s important to acknowledge the broader context of fluctuating birth rates since the pandemic began. Births initially rose in some countries early in the pandemic, but then declined as the public health emergency eased. In the US, the fertility rate reached a record low in , falling to less than 1.6 children per woman, according to data from the Centers for Disease Control and Prevention.
Researchers suggest that these declines are likely driven by a complex interplay of factors, including economic uncertainty, job insecurity, inflation, and changes in lifestyle and priorities related to the pandemic. It’s also important to note that the general fertility rate in the US was already at an all-time low before the onset of the COVID-19 pandemic, suggesting that the recent decline is part of a longer-term trend.
Importantly, the evidence indicates that contracting COVID-19 during pregnancy poses significant risks to both mother and baby. Studies have shown that pregnant women who contract the virus face a higher risk of severe illness, hospitalization, and even death compared to non-pregnant women. COVID-19 infection during pregnancy has also been linked to increased risks of pregnancy complications, such as hypertension, preeclampsia, preterm birth, and stillbirth.
Conversely, research demonstrates that pregnant women who are vaccinated against COVID-19 are far less likely to be hospitalized, require intensive care, or deliver prematurely compared to unvaccinated pregnant women. Children born to mothers who had COVID-19 while pregnant may face an increased risk of developmental disorders, including speech delays and autism, and may have weakened immune systems.
Health experts continue to emphasize that vaccination remains the most effective way to protect against severe COVID-19 illness, hospitalization, and death. While federal guidance in the US has evolved, with the removal of the COVID vaccine from the list of routinely recommended shots for healthy pregnant women and children, the CDC now recommends “shared clinical decision-making” regarding vaccination. Major medical groups, including ACOG and the Society for Maternal-Fetal Medicine, continue to recommend COVID-19 vaccination for pregnant and breastfeeding women.
