New research on Covid-19 vaccines confirms that they have no effect on fertility or early pregnancy.
In this field, data on natural pregnancies among vaccine trial participants were reassuring from the outset, as it was found that pregnancy rates were equally frequent in both the vaccine and control groups. Now, two new studies corroborate these findings.
In one article, the journal Obstetrics & Gynecology reports the results of the study In Vitro Fertilization and Early Pregnancy Outcomes After Coronavirus Disease 2019 (COVID-19) Vaccination, in which researchers from the Icahn School of Medicine at Mount Sinai (Icahn Mount Sinai) in New York City and the Reproductive Medicine Associates of New York (RMA of New York) compared fertility rates, pregnancy and early miscarriage among in vitro fertilization (IVF) patients who had received two doses of the Pfizer or Moderna vaccine, and obtained the same results as in unvaccinated patients.
While the study entitled A prospective cohort study of COVID-19 vaccination, SARS-CoV-2 infection, and fertility, published in the American Journal of Epidemiology, compares the ability to conceive naturally between vaccinated and unvaccinated couples and concludes that vaccination against Covid-19 does not affect the fertility of either partner, although men who become infected with coronavirus may experience a reduction in fertility in the short term.
COVID-19 vaccination is safe and recommended for pregnant women
Eugin Group’s scientific director, Rita Vassena, stresses that “the data available since the start of mass vaccination programmes have always shown that the vaccine does not affect fertility”. However, she points out that it is important to continue studying the question, as unfortunately there is still some resistance to vaccination among those who are considering pregnancy or who are already pregnant.
According to Vassena, the reluctance is due to several factors such as, for example, the lack of inclusion of pregnant women in clinical trials for vaccines (a lack that has been made up for with real-world data as soon as vaccination became widespread); and the presence of specific alterations in the menstrual cycle among many women after vaccination. However, these recent studies add to the evidence and strengthen the recommendation to vaccinate.
“It is worth remembering that, while the vaccine does not affect fertility or pregnancy outcomes, having Covid-19 does carry a higher risk of hospitalization in pregnant women, as well as a more severe clinical presentation of the disease. Furthermore, new evidence suggests that Covid-19 is also associated with ongoing pregnancy losses,” says Vassena. However, there are no perceived adverse effects of the vaccine on women’s reproductive function, and it is important to be vaccinated to protect both mother and baby.
Assisted reproduction treatments provide more information on COVID-19 vaccines
Dr. Vassena also stresses that pregnancies resulting from assisted reproduction techniques allow us to analyse reproductive details that are beyond the scope of epidemiological studies, such as how the ovary responds to reproductive hormones; whether there are alterations in egg quality; or whether there are very early pregnancy losses (these go unnoticed in population-based studies, as the pregnancy ends in the first 2-3 weeks, before it is even recognised as such).
These details, which are discussed in the study published in the journal Obstetrics & Gynecology, confirm and build on the evidence already available: no proof has been found that the vaccine has negative effects on fertility.
Related press articles:
- Vaccines and menstruation: evidence of mild, temporary and minor disturbances to those caused by covid (Newtral)
- Vaccination against covid-19 does not affect fertility or the onset of pregnancy (La Sexta)
- Vaccination against covid-19 does not affect fertility or the onset of pregnancy (Agencia SINC)