Pill heightens blood clot risk for obese women

Obese women who take the contraceptive pill are up to five times more likely to develop potentially fatal blood clots, research has shown.

Current guidelines allow women with a body mass index (BMI) in excess of 30 – at which point they are classified as obese – to take oestrogen-based contraceptives, but new research indicates that the risk of life-threatening blood clots is greater than previously thought.

The European Active Surveillance (Euras) study looked at 59,000 women from seven countries including Britain and found that the number of blood clot cases among obese women was five times greater than among patients not on the contraceptive pill.

In an interview with the Daily Mail, Dr Anne Szarewski, editor-in-chief of the Journal of Family Planning and Reproductive Health Care, said that the study showed that the risk of blood clots for obese women on the contraceptive pill was high.

“We have known that obesity is a risk factor but it was previously assumed the absolute risk was quite low compared with women not taking the contraceptive pill, but these findings show it’s five times higher,” she revealed, adding that she has stopped prescribing the pill to women with a BMI over 30.