Taking birth control pills or combined oral contraceptives containing both oestrogen and progestin may triple the risk of cryptogenic stroke in young women, according to a study.

Strokes without a known cause are called cryptogenic. It accounts for up to 40 per cent of all ischaemic strokes in young adults. Despite its prevalence, the contribution of sex-specific risk factors, such as contraceptive use, has remained underexplored.