Newly released text messages have reignited debate over the safety of COVID-19 vaccines for pregnant women, with some messages suggesting that former chief medical advisor Dr. Anthony Fauci privately expressed concerns. While public statements from Fauci indicated no risk, the released communications have prompted individuals, including TV personality Meghan McCain and billionaire investor Bill Ackman, to share personal experiences of miscarriage during the pandemic. However, neither specified if these miscarriages occurred after COVID vaccination.
A 2021 study that initially suggested an 82% miscarriage rate among vaccinated first-trimester pregnancies was later acknowledged by its authors to have a flawed design and misinterpreted calculations. The Centers for Disease Control and Prevention (CDC) stated that the 82% figure was not an appropriate calculation because outcomes for many ongoing pregnancies were not yet known. The study authors also noted that data was missing for many women vaccinated early in pregnancy, making early-pregnancy miscarriage rates difficult to calculate.
Subsequent and broader research, including studies analyzing tens of thousands of pregnant women, has found no evidence that COVID-19 vaccines cause or increase the risk of miscarriages. These studies, such as a 2021 analysis of over 105,000 pregnant women in the U.S. and a Norwegian study of nearly 18,000 pregnant women, found similar rates of miscarriage among vaccinated and unvaccinated individuals. The CDC reports that over a million pregnant women have received COVID-19 vaccines, and its monitoring systems show no higher risk of miscarriage.
Scientists have not identified a difference in risk depending on the trimester of pregnancy, and concerns about increased miscarriage risk in the first trimester have not been supported by studies. Further research has also indicated no higher risk of preterm delivery, low birth weight, or birth defects for the fetus when the mother is vaccinated. The Society for Maternal-Fetal Medicine (SMFM) reaffirms its recommendation for pregnant patients to receive the COVID-19 vaccine.
Miscarriage is a common occurrence, with estimates suggesting 10 to 20 percent of U.S. pregnancies end in miscarriage before 20 weeks gestation. Experts note that many miscarriages go unreported, and in a majority of cases, a definitive cause is never identified. Factors such as maternal age over 35, diabetes, obesity, uterine conditions, and smoking can increase risk. Experts suggest that due to the commonality of miscarriages, some cases linked to vaccines or the virus may have occurred regardless.
While widespread immunity to COVID-19 now exists, some doctors maintain that vaccines still offer benefits. Pregnant women infected with COVID-19 are at a higher risk of hospitalization, needing advanced life support, and have an increased risk of preterm birth and stillbirth compared to non-pregnant individuals. However, hospitalizations due to COVID-19 infection are currently at record low rates nationwide.
Current recommendations for COVID-19 vaccination in pregnant women vary. The CDC does not currently recommend COVID-19 booster shots for pregnant women. In contrast, the American College of Obstetricians and Gynecologists (ACOG), along with 13 other medical bodies, urges expectant mothers to get the vaccine. ACOG's June schedule advises pregnant women to receive the Tdap and RSV vaccines, in addition to COVID-19 and flu vaccinations, with the COVID-19 vaccine being administrable at any point during pregnancy. In other countries, such as the UK, the COVID-19 vaccine is not routinely recommended for pregnant women unless they are at high risk.
There is no scientific evidence to suggest that COVID-19 vaccines affect fertility in the long term, nor is there evidence that COVID-19 impacts reproductive organs directly.