New contraceptive leads to blood clot risk - study

Certain types of contraceptive pills lead to a higher risk of potentially life-threatening blood clots, New Zealand led research has found.

The study, co-authored by Lianne Parkin of the University of Otago, found British women who took a combined oral contraceptive pill containing the progestogen hormone drospirenone were more likely to develop venous thromboembolism, which is a rare condition involving blood clots in the legs.

Each year about 23 women per 100,000 users of the drospirenone pill developed the condition compared to nine per 100,000 for those taking older types of pills containing levonorgestrel.

"In other words, among women taking the drospirenone oral contraceptive, each year an extra 14 women per 100,000 users suffered a venous thromboembolic event which could have been avoided if they had been taking a levonorgestrel pill instead," Dr Parkin said.

The results were consistent with two previous studies, she said.

Drospirenone is not widely used in New Zealand because it is not subsidised. It is found in Yasmin, Yaz and Yasminelle.

- NZPA