Observer analysis finds unregulated products being promoted as contraception despite concerns about their accuracy

Apps promising to help women “take control” of their sex lives by predicting the days when they are fertile are putting users at risk of unplanned pregnancy by making misleading claims.

Millions of women in the UK – including 69% of 18-24-year-olds – have used smartphone apps that track their periods. Many also tell them their “fertile window”: the days when they are most and least likely to get pregnant.