Data shows that almost 4,000 women have experienced heavier periods than usual, or noticed other changes to their menstrual cycle, after receiving the coronavirus vaccine.
2,734 reports of menstrual changes came following the AstraZeneca vaccine. They were reported to the Medicines & Healthcare products Regulatory Agency (MHRA) before May 17, according to official data obtained by the Sunday Times.
A further 1,158 reports came from women after receiving the Pfizer jab, and there were 66 linked to the Moderna vaccine.
It is said that these menstrual changes have largely affected women between the age of 30 and 49.
Changes in the menstrual cycle are not currently listed as a possible side effect after receiving the vaccination.
It is thought that any changes to a woman’s period after receiving the vaccine is linked to the body’s immune system response, which the womb lining is a part of.
These changes are said to be nothing to worry about and will only be temporary for those who do experience them.
Many scientists believe it is merely coincidental that women are experiencing these changes after their Covid jab.
Vice president for membership at RCOG, Dr Pat O'Brien, said: "Many women will experience a temporary change in their periods from time to time during their lives.
"And right now, many women in their 20s and 30s are having the COVID vaccine.
"So it seems inevitable that in some women these two events will coincide by chance."
The MHRA also said: “The current evidence does not suggest an increased risk of either menstrual disorders or unexpected vaginal bleeding following the vaccines.
“The number of reports of menstrual disorders and vaginal bleeding is low in relation to both the number of females who have received Covid-19 vaccines to date and how common menstrual disorders are generally.
“The MHRA will continue to closely monitor reports of menstrual disorders and vaginal bleeding with Covid-19 vaccines.”
More than 43 million people across the UK have been vaccinated, amongst those are 31 million people who have already received their second dose of the Covid vaccine.
Over 18s are now being offered to book their vaccinations in and the vaccine rollout continues.
