Women using fertility apps and websites to work out when they are most likely to get pregnant could be getting bad advice, a study has warned.
Tests were carried out on 20 websites and 33 apps designed to help predict a woman's fertility window - the days before ovulation when having sex is most likely to result in conception.
Usually, a woman with a standard 28-day menstrual cycle will ovulate around day 15, which would also be the last day of a six-day fertile window.
While most reliably predicted the day of ovulation, only four provided the correct fertile window the study found.
This suggests thousands of women are being wrongly informed about when they are most likely to conceive.
Digital Sociology; Health