Washington DC: Ladies! You may want to avoid using oral contraceptives as a new study has suggested that birth control pills pose a small but significant risk of the most common type of stroke.
For healthy young women without any stroke risk factors, the risk of stroke associated with oral contraceptives is small, but in women with other stroke risk factors, the risk seems higher and, in most cases, oral contraceptive use should be discouraged, as per the Loyola University Health System study.
Strokes associated with oral contraceptives were first reported in 1962. Early versions of the pill contained doses of synthetic estrogen as high as 150 micrograms. Most birth control pills now contain as little as 20 to 35 micrograms. None contain more than 50 micrograms of synthetic estrogen.
Oral contraceptives increase the risk of ischemic strokes, which are caused by blood clots and account for about 85 percent of all strokes. In the general population, oral contraceptives do not appear to increase the risk of hemorrhagic strokes, which are caused by bleeding in the brain.
There are about 4.4 ischemic strokes for every 100,000 women of childbearing age. Birth controlpills increase the risk 1.9 times, to 8.5 strokes per 100,000 women, according to a well-performed "meta-analysis" cited in the report. This is still a small risk; 24,000 women would have to take birth control pills to cause one additional stroke, according to the report.
But for women who take birth control pills and also smoke, have high blood pressure or have a history of migraine headaches, the stroke risk is significantly higher. Such women should be discouraged from using oral contraceptives, the report said.
Hormone replacement therapy with estrogen alone or combined with progesterone increases the risk of ischemic stroke by 40 percent; the higher the dose, the higher the risk, the report said.
The study appears in the journal MedLink Neurology.