Long covid may be making your periods longer and heavier

Long covid seems to disrupt the menstrual cycle, making periods heavier and longer. This may come about because of lingering covid-19-related complications that alter levels of hormones or cause inflammation.

Why long covid occurs is unclear – studies suggest it may result from the virus lurking at low levels in the body, the immune system misfiring or even disruption to the gut microbiome.

Common symptoms include fatigue and brain fog; it has also previously been linked to menstrual cycle disruption, but these studies didn’t report the exact changes to menstruation that occurred. They also didn’t uncover whether these changes might happen anyway, regardless of whether someone catches covid-19, or if they occur following a short-lived infection.

To fill this gap, Jacqueline Maybin at the University of Edinburgh, UK, and her colleagues recruited more than 12,000 women to complete a survey on their reproductive health between March and June in 2021.

More than 9000 of them had never had covid-19, defined as not testing positive for the virus or not having had symptoms associated with it, such as loss of smell or a dry cough. About 1700 of the women had experienced acute covid-19, where any symptoms disappeared within a month, while the remaining 1000 participants had long covid, which the researchers defined as having symptoms that persisted for more than a month after a known or suspected infection.

More than half of those with long covid reported having periods that were heavier than usual for them. This figure was about 40 per cent among the women who had acute covid-19, and 35 per cent among those who were never knowingly infected.

Long covid was also more strongly linked to having periods that last for more than eight days. Acute covid-19 seemed to have no effect on period length, suggesting that specific changes occur to the body with long covid, rather than with the infection itself.

To find out what mechanisms may be at play, the researchers analysed samples of circulating blood, collected from across the menstrual cycle of 10 women with long covid and 40 women who made donations before the pandemic.

This revealed that those with long covid tended to have higher levels of a certain hormone, called 5α-dihydrotestosterone – which has been linked to irregular periods – during the second half of their menstrual cycle. The team also linked long covid to higher levels of inflammatory molecules called cytokines in the blood and uterine lining, collected via biopsies.

This suggests that long covid may cause hormonal and immune changes that disrupt the menstrual cycle, but further studies are needed to clarify this, says Maybin.

In another analysis, the team found that women with long covid reported experiencing worse symptoms – such as dizziness, fatigue and muscle aches – just before and during menstruation, while nausea, headache and breathing issues tended to get worse during the phase after menstruation and before ovulation. “That’s a signal that ovarian hormones may actually be contributing to the severity of some symptoms,” says Maybin.

But as the study mainly involved white women, all of whom lived in the UK, a high-income country, further studies are needed to see if the results apply to more diverse populations, she says.