New forms of the contraceptive pill dramatically raise the risk of potentially lethal blood clots for women taking them, according to a study.

• Forget the dadbod, what about the mumbod?

So-called “third generation” contraceptive pills such as Yasmin, Marvelon and Femodene raise the risk of a blood clot as much as four times compared with women who don’t take the drug, research from Britain’s University of Nottingham, published in the British Medical Journal, found.

The overall risk for women taking the contraceptive pill was nearly three times that of women not taking the drug.

Third generation contraceptive pills were introduced in the 1980s. Drug developers altered the progesterone contained in drug to reduce side effects such as acne, weight gain and breakthrough bleeding – but the flipside was an increased risk of blood clots.

Blood clots are relatively rare but can be serious. They usually form in the legs, but if they lodge in the lungs they can form a potentially fatal blockage or if they move to the brain they can trigger a stroke.