Covid vaccine-related menstrual disorder: the cycle extended by one day, a study found

Published by Cécile D. · Published on 7 January 2022 at 15h56
Covid-19 vaccines have caused many menstrual disorders, as shared by many women. Released this January 5, 2022, an American study acknowledges the vaccine can somewhat disturb the menstrual cycle, but effects remain harmless.

We know after getting injected one of Covid-19 vaccines we can feel fatigue, muscle pains, or headache. For several weeks, many menstruated people have been complaining about menstrual cycle disorder. After several testimonies and complaints, the Agence nationale de sécurité du médicament – Medicines Safety National Agency – has stated menstrual disorder is now part of vaccines likely side effects. This disorder has been placed under surveillance on a European level.

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In their report from July 30, 2021, the ANSM writes: “The assessment of menstrual disorder cases following vaccination with Spikevax [Moderna’s other name – Editor’s note] (36 cases since vaccination started) has led the follow-up committee to consider this is a potential signal also involving Comirnaty [or Pfizer – Editor’s note], which profile is similar. This potential signal will be carried out to a European level”.

In stories shared on social networks, women are complaining about heavier periods, irregular cycles, abnormally acute pains, and even unexplained lack of their periods following Covid-19 vaccination.

On France Info, Leane Alestra confesses: “After my first dose, I have had no side effect related to my menstrual cycle. But, after my second dose, within ten days, I noticed new period, while it was absolutely not usual with my cycles, lasting about 30 days. This is something that never happened to me in 12 years of menstruations”.

These new disorders are not necessarily worrying, according to gynecologist-obstetrician Olivier Picone. This doctor, working at Colombes Louis-Mourier hospital and member of the National College of French Gynecologists and Obstetricians (CNGOF) explains in Le Parisien daily a “menstrual cycle is easily disturbed”. Stress, lack of sleep, or an infection can cause these issues.

Since the vaccine aims at causing a strong body response to exterior attacks, these menstrual disorders can be seen as normal. Gynecologist and President of the CNGOF Medical Gynecology Committee Geoffroy Robin claims: “This is not the vaccine that is the direct cause of a menstrual disorder but the inflammatory reaction it induces”.

Yet, bonds between menstrual disorders and vaccination have not been proven yet. On France Info, gynecologist Christian Jamin reminds disorders are common. “Nothing enables us to make the bond between vaccine and the outbreak of these disorders. To do so, we should have to carry out “control-case” studies, namely pairing women who have been vaccinated and others who have not, and see if there is a difference. It should be seen as an alert, but it certainly should not cause worries today, given results reported”, the doctor says, intending to be reassuring.

Temporary and trivial disorder

This Wednesday September 29, French Health Minister Olivier Véran intended to sound reassuring: this disorder felt after the vaccine is not serious, and there is no reason to be worried.

Interviewed by France Inter, the minister explains: "What the ANSM says - that recorded a certain number of reports about temporary and mild disorders, which does not mean they can be lived well - is that this is not serious and nothing definitive can impact women's menstrual disorder who have been vaccinated".

Olivier Véran insists this menstrual disorder is not serious and especially "temporary and does not impact fertility" and as per usual, the minister's goal is to vaccinate as many French people as possible.

On Wednesday January 5, 2022, the menstrual disorder topic is back thanks to an American study released in the Obstetrics & Gynecology magazine. Searchers have assessed cycles of about 4,000 women aged 18 to 45, and using no contraception, via an application enabling to watch one's menstruation cycles. In this sample of the population, 2,400 participants were vaccinated (with Pfizer, Moderna or Janssen), and 1,500 were not.

Scientists have noticed vaccinated women's cycles were extended by about one day, a temporary and harmless impact, they say. In all, results of this study "are very reassuring" for women, Professor of Obstetrics and Gynecology and Director of the OHSU Complex Family Planning Section and Fellowship Alison Edelman said.

Practical information