Some hormonal contraceptives used as alternatives to the pill -- such as skin patches, implants and vaginal rings -- carry a higher risk of serious blood clots, new research shows.
The study, published online in the British Medical Journal, suggest women on such non-oral contraceptives switch to a birth control pill to reduce their risk.
Several studies have found blood clot risks are higher in women using oral contraceptive pills. But the new research – conducted by the University of Copenhagen – is among the first studies to assess the negative effects of non-oral contraceptives that continuously release hormones into the body to prevent pregnancy.
For the study, Øjvind Lidegaard and colleagues tracked the health records of more than 9,400 Danish women – aged 15 to 49 – from 2001 to 2010. They found the risk of blood clots was three times as likely among those taking the hormonal contraceptives than those who did not. Women who used a skin patch were even more likely to experience clots -- eight times the risk of non-users.