Do Covid-19 vaccines increase the risk of infertility, miscarriage or menstrual disorder?

“Transparency is essential to convince those who have doubts about vaccination,” said Minister of Health Franck Vandenbroucke (sp.a) at the microphone of La Libre Belgique on July 14. And for good reason: some of the reasons given by Belgians to explain a refusal to be vaccinated are based on false information circulating on the internet. In addition to the lack of hindsight of scientific laboratories, anti-vaccines are particularly concerned about the risks of miscarriages, infertility or menstrual disorders.

The Source has decided to deconstruct some of these claims, which are particularly widespread on social networks.

1. The Covid-19 vaccine is a danger to the mother or the fetus

For the scientific and medical communities, no link has been established between vaccination against the coronavirus and harmful effects for current or future pregnancies. In Belgium, the official voice to follow is that of the Superior Health Council (CSS). Its recommendations are formal: “currently available RNA vaccines against COVID-19 can be safely administered to pregnant women”. The RNA vaccines are those of the Pfizer and Moderna laboratories.

The CSS recommendations are based in particular on the preliminary results of an American study, published on June 17, 2021 in the New England Journal of Medicine. Conducted among more than 35,600 pregnant women, this study did not show any alarming signals in participants who received a Moderna or Pfizer vaccine. If the miscarriage rate (13.9%) noted in this study has caused some Internet users to react, it is nevertheless “similar to the incidences reported in studies (…) carried out before the Covid-19 pandemic”, can we read in the conclusions.

What about the messages denouncing the clinical trials launched by the Moderna laboratory on July 22 with 1,000 pregnant women to assess the risks of miscarriage, as can be read on the tweet reproduced above? These tests are mainly aimed at “dispelling fears”, says Doctor Oranite Goldrat, gynecologist at the Erasmus Hospital in Brussels. “Although studies conducted previously did not show a problem with miscarriages, they did not specifically target pregnant women. These tests will make it possible to obtain regulated results on this specific category of the population”, specifies the gynecologist.

The double benefit of vaccinating pregnant women

For the ULB epidemiologist, Muriel Moser, vaccination for pregnant women represents a double advantage: “we prevent women from contracting the disease by almost 95% and we also protect babies after birth: there is antibodies that pass through the placenta or into the milk if the mother is breastfeeding”.

Catching Covid-19 can be dramatic if you are pregnant. The cases of serious forms of the coronavirus being higher for them than for the rest of the population, recalls the World Health Organization, and “not only among pregnant women with comorbidities such as obesity or diabetes”, specifies gynecologist Dr. Oranite Goldrat. An international study published in April 2021 in the scientific journal JAMA Pediatrics thus showed an increase in maternal mortality and premature deliveries in women who contracted Covid-19 during their pregnancy.

Faced with these risks, the CSS estimated last April that all pregnant women had priority for vaccination compared to a non-pregnant woman.

2. Getting vaccinated against Covid-19 in early pregnancy increases the risk of miscarriage

Several information circulating on social networks return to the fact of having to respect a minimum number of weeks of amenorrhea before being vaccinated against Covid-19. “This delay was above all a precautionary principle at the start of the vaccination campaign,” says Dr. Oranite Goldrat. « Today, with all the studies carried out and the vaccinations carried out without any particular risks being observed, this delay in the first trimester of pregnancy is no longer the rule today in Belgium ».

Same speech in France, where the Minister of Health, Olivier Véran, reaffirmed on July 20 that vaccination was open to pregnant women from the first month of pregnancy.

Some doctors like Doctor Isabelle Dehaene, gynecologist at UZ Gent, advocate vaccination “before the third trimester of pregnancy” during which the serious side effects of the coronavirus “are higher for the baby”.

3. Messenger RNA vaccines alter fetal DNA

Many studies, articles and publications (here, here or there) have shown that messenger RNA vaccines do not modify the DNA of inoculated patients. The same goes for pregnant women and their unborn babies.

These vaccines are even preferred for this particular public, especially in Belgium. The reason ? “We have more experience with Pfizer and Moderna, based on observational cohorts of thousands of women who have received these vaccines with messenger RNA for months around the world”, underlines Doctor Isabelle Dehaene.

Among these cohorts are the 35,600 pregnant women participating in the US New England Journal of Medicine study cited above for which there were no « increased risks of serious side effects or adverse pregnancy outcomes due to Moderna or Pfizer/BioNTech vaccines”.

According to Doctor Isabelle Dehaene, quoting an internal source from the vaccination task force, “more than 25,000 Belgian pregnant women have already been vaccinated with one of these two vaccines”.

4. Covid-19 vaccines make you infertile

“We must put an end to this fake news of the impact of the vaccine on infertility, it came out of nowhere (…) it is neither rational nor biologically based”, answers Nicolas Dauby, infectiologist at the Saint Hospital Center Rock.

The World Health Organization (WHO) has reaffirmed the unfounded nature of this rumor, in a video published on June 4. Dr. Soumya Swaminathan can be seen saying: “There is absolutely no scientific evidence or truth behind this concern that vaccines interfere in any way with fertility, either in men or women. in women”.

The results of a study carried out on 36 couples planning in vitro fertilization (IVF) also point in this direction. “The RNA vaccine did not affect the performance or ovarian reserve of patients in their immediate next IVF cycle,” reads the conclusion of this study published in May 2021 in the journal Reproductive Biology and Endocrinology.

Concerning a possible disruption of the rules, the post-vaccination immune response has not, for the moment, revealed a modification of the menstrual cycle according to Muriel Moser. “A randomized scientific study should be carried out on this subject” adds epidemiology.

Ultimately, rumors of miscarriage, infertility or modified DNA due to vaccines are unfounded, even dangerous for the mother and her child. “The benefit of vaccination in pregnant women therefore outweighs the potential risk of side effects and avoids the danger of severe complications in the event of Covid-19 contracted during pregnancy”, argues Dr. Goldrat of Erasmus Hospital.

This section aims to analyze, dissect, recontextualize and verify facts related to current events. As the very notion of « fact checking » indicates, the approach is based exclusively and systematically on a factual analysis, the collection of verifiable, identifiable and objectifiable sources, cited and referenced in each of our articles. The reader who wishes to do so is free to redo this journalistic work on the basis of the information provided, and to report any errors or inaccuracies to us via the address factchecking@lalibre.be or this online form.

Read our editorial charter