Study links birth control pill to stroke risk
Researchers studied 536 women aged 18 to 49. Half had suffered cryptogenic strokes, and the rest were healthy.
A new study has raised safety concerns over the widely used combined oral contraceptive pill, linking it to a higher risk of stroke, even as its use in Kenya continues to grow.
According to the Kenya National Bureau of Statistics, the number of new users of the combined pill rose from 191,487 in 2023 to 294,172 in 2024, an increase of more than 100,000 users in just one year.
Repeat visits also grew sharply, from 312,825 to 498,506, signalling rising reliance on the method.
However, new research presented at the European Stroke Organisation Conference in Helsinki suggests that women taking the pill may face a higher risk of suffering a cryptogenic ischemic stroke, a stroke with no identifiable cause.
Researchers studied 536 women aged 18 to 49. Half had suffered cryptogenic strokes, and the rest were healthy.
Of the stroke patients, 66 were using the combined pill, compared to 38 in the stroke-free group.
After adjusting for age and other health conditions, the study found that women on the pill were three times more likely to suffer this kind of stroke.
"Our findings confirm earlier evidence linking oral contraceptives to stroke risk and should prompt more careful evaluation of stroke risk in young women, particularly those with additional risk factors," said Dr Mine Sezgin, a neurology expert from Istanbul University who led the study.
"This knowledge could help guide more personalised contraceptive choices for women."
The combined pill contains both oestrogen and progestogen and works by preventing ovulation.
Though some earlier studies linked its use to stroke risk, this new research suggests a direct connection between the pill and stroke, independent of known risk factors like obesity, high blood pressure or migraines.
Dr Sezgin said the strong link found even after adjusting for other risk factors points to possible genetic or biological causes.
"While our data provides important initial insights, larger studies are needed to determine whether certain formulations carry different levels of risk," she added.
Globally, more than 100 million women use the combined pill, which is more than 99% effective at preventing pregnancy when used correctly.
It is also prescribed for other conditions like heavy periods, premenstrual syndrome, endometriosis and acne, according to the World Health Organisation.
Independent experts have urged caution, noting that the absolute risk of stroke in young, healthy women remains very low, and that pregnancy itself carries a higher risk of stroke than contraceptive use.
