Chiara Frendo-Balzan, a gynaecologist, explains why some women might experience a delay in their menstrual cycle after taking a vaccine dose.

Preparing for your COVID-19 vaccine appointment, you are informed about a number of common possible side effects –  a sore arm, tiredness, headaches or loss of appetite. But what about any effects to a woman’s menstrual cycle?

Whilst the health authorities have shut down claims that COVID-19 vaccines cause infertility, it has not provided any information on whether the vaccine could affect women’s periods.

Chiara Frendo-Balzan, a gynaecologist at Willingness Clinic, said that, in the past four weeks, she has received at least three messages a day from women who have noticed a delay or abnormality in their period after taking a COVID-19 vaccine.

“In the past year, I have seen a number of women who struggled with menstrual change, especially linked to increase stress due to the COVID-19 situation but, recently, I noticed a difference since we started vaccinating women who are still menstruating,” she said.

She spoke about the reasons why women could be experiencing these changes and why they should not worry.

What effects are women experiencing after taking the coronavirus vaccine? Do such changes happen after the first or second dose?

This varies considerably. Some women who had taken the vaccine whilst on their period reported that their period suddenly stopped. For example, someone’s period would last for only two or three days, when it would usually last for seven.

I have also had women who had erratic cycles, meaning that the gap between one period and the other keeps changing, or can come early or late. This happens especially if their vaccine was taken in the middle of their cycle.

Some have reported that their period is late and this would cause some anxiety.

Some women have sought help thinking they have some hormonal imbalance. Others have had an unusual heavier or more painful period but the irregularity in their cycle seems to be more common.

How old are the women who have come forward experiencing such changes? Are some women post-menopausal?

Ages vary but, in my experience, mostly women in their late 30s or 40s have noticed these changes.

I have also recently seen an increased incidence of peri-menopausal bleeding or post-menopausal bleeding in women who took the vaccine.

Yet, it is difficult to assert if it is from the vaccine or not because we would need to exclude other menstrual cycle and hormonal changes women experience at that age.

So far, we only have a few months data and, as yet, the vaccine has not been shown to reduce fertility

How does the vaccine effect the menstrual cycle?

The COVID vaccine works by creating an immune response in the body to trigger the production and release of specific antibodies against the novel coronavirus.

This immune response is strong and cause a significant impact as it is perceived as stress by the body, which could cause an imbalance of hormones.

We know that if a women is stressed, the last thing the body needs is a pregnancy and that could be a physiological response to shut down the hormonal feedback from the womb lining (which is part of the immune system too), even if temporarily.

As far as I know, there has been no particular research on this and no statistical evidence, however, it is not to be ignored because of the recent increased number of irregular menstrual cycles that I have seen, which I would say is significant.

Could these side effects be long-term? Should women be concerned?

I don’t think these are long-term repercussions.

I would not suggest that women stress about this, however, if their irregularities remain for more than a couple of  months it is important to seek medical advice.

I also would not recommend avoiding the COVID vaccine because it might cause you to miss a period. This does not happen to everyone. It is always best to discuss with your doctor if you have concerns.

Does the COVID-19 vaccine affect fertility?

As far as we know the vaccine does not affect fertility.

So far, we only have a few months data and, as yet, the vaccine has not been shown to reduce fertility. It is also advised that women trying to conceive or on a waiting list for IVF can still proceed with their vaccine appointments.

Can a woman take the vaccine if she is pregnant or breastfeeding?

In Malta we are not vaccinating pregnant women. However, other countries are and this is an area for research.

The vaccine does not affect breastfeeding, so it is recommended that these women still take their vaccine as it does not go to the breast milk.

Independent journalism costs money. Support Times of Malta for the price of a coffee.

Support Us