June 15, 2012
Could Your Birth Control Cause Heart Attack and Stroke?
(Ivanhoe Newswire) -- A 15-year Danish historical cohort study was done to see how hormonal contraception can cause thrombotic stroke (blood clotting inside a brain artery) and myocardial infarction (heart attack).
In this study, 1,626,158 non-pregnant women from the ages of 15 to 49 years old were observed. During the study 3,311 thrombotic strokes and 1,725 myocardial infarctions occurred.
The current use of oral contraceptive that included ethinyl estradiol (bio-active estrogen) at a dose of 30 to 40 µg was associated with the following risks for thrombotic stroke and myocardial infarction, according to progestin type: norethindrone, 2.2 and 2.3; levonorgestrel, 1.7 and 2.0; norgestimate, 1.5 and 1.3; desogestrel, 2.2 and 2.1; gestodene, 1.8 and 1.9; and drospirenone, 1.6 and 1.7, respectively.
Using ethinyl estradiol at a dose of 20 µg, the corresponding relative risks according to progestin type were as follows: desogestrel, 1.5 and 1.6; gestodene, 1.7 and 1.2; and drospirenone, 0.9 and 0.0.
For transdermal patches, the corresponding relative risks were 3.2 and 0.0, and for a vaginal ring, 2.5 and 2.1.
Although the absolute risks of thrombotic stroke and myocardial infarction associated with the use of hormonal contraception were low, the risk was increased by a factor of 0.9 to 1.7 with oral contraceptives that included ethinyl estradiol at a dose of 20 µg and by a factor of 1.3 to 2.3 with those that included ethinyl estradiol at a dose of 30 to 40 µg, with relatively small differences in risk according to progestin type.
Source: New England Journal of Medicine, June 2012