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More than 13,000 women report period changes after COVID vaccine

Published on 21/07/21 at 08:16am

The number of women who have reported changes to their period to the MHRA after having the COVID vaccine has risen to 13,000, as reported in Sky News.

Changes to menstruation are not listed as a formal side effect of the vaccine and much of the information is currently anecdotal.

Experts say there is no evidence to believe the vaccines affect fertility, however there are reports that some women are refusing to get the jab.

Women whose periods appear to have been affected by the jab have called for information and advice to be made more readily available.

Dr Kate Clancy, a medical anthropologist, shared on Twitter her experience of an unusually heavy period following the Moderna vaccine, and received many responses from women with similar experiences. With former colleague Dr Katharine Lee, she launched a survey documenting people's experiences, as reported in BBC.

There’s no way of knowing for sure whether the vaccine is causing these changes as it hasn't been studied. It's possible that women post-vaccination are more likely to notice or attribute changes, particularly after hearing about others' experiences.

But Dr Victoria Male, a reproductive immunologist at Imperial College London, said some post-menopausal women, and people taking hormones which stop their periods, have reported bleeding, she's inclined to suspect there may be a physical reaction occurring.

However, Dr Male said women should feel confident getting the jab and that reports of changes are not unexpected, as similar reactions have been observed with the flu vaccine.

She told Sky News that 25% of women who contract COVID-19 also see changes to their period.

She said: "We know that sex hormones affect the immune system and the immune system affects sex hormones and we have some evidence that the flu vaccine, given a certain time in your cycle, can slightly dampen the amount of progesterone you have, and it's the balance between oestrogen and progesterone that builds up and breaks down the lining of your uterus.

"So if these get slightly out of whack then we might expect to get a heavier period or a later period.”

Dr Male also said there is no scientific link between the vaccination and fertility and warned that women can be more susceptible to problems during pregnancy if they contract COVID-19.

Lilly Subbotin

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