Women who use some non-oral forms of hormonal contraception are at higher risk of blood clots than those not taking any hormone-based birth control, a Danish study suggests.
In Friday’s issue of the British Medical Journal, Professor Øjvind Lidegaard at the University of Copenhagen reviewed data on risks of the patches and rings for venous thrombosis among all Danish non-pregnant women aged 15 to 49 from 2001 to 2010.
During the study period, the researchers found 3,434 confirmed diagnoses of venous thrombosis — a clot blocking a vein or artery.
While the risks of blood clots in women using birth control pills containing drospirenone came to light in 2010, the risks of contraceptive skin patches and vaginal rings haven’t been studied as much.