London,
Women who use hormonal contraceptives, including birth control pills, are at an increased risk of breast cancer, a study warns.

The findings, published in The New England Journal of Medicine, are based on a study that followed 1.8 million women between 15 and 49 years of age for more than 10 years.

Researchers from the University of Copenhagen in Denmark said the risk of breast cancer was higher among women who recently used contemporary hormonal contraceptives than among women who had never used hormonal contraceptives. However, absolute increases in risk were small.

After discontinuation of hormonal contraception, the risk of breast cancer was still higher among the women who had used hormonal contraceptives for five years or more than among women who had not used hormonal contraceptives.

Women who currently or recently used the progestin-only intrauterine system also had a higher risk of breast cancer than women who had never used hormonal contraceptives.