A new study on the safety of hormone replacement therapy (HRT) suggests the risk of ischemic and hemorrhagic stroke increases during the first six months of treatment. In a report published in this month's issue of Archives of Internal Medicine, researchers from the University of Washington in Seattle describe a case-control study involving nearly 1,000 women who had suffered either an ischemic or hemorrhagic stroke.

The report indicates that during the first six months of HRT use, the risk of stroke increased more than two times. The scientists also discovered that high estrogen use (more than 0.625 mg) was associated with a two and one half-fold increase in ischemic stroke. The study's findings support data from several studies conducted this summer that indicated HRT does not prevent strokes in postmenopausal women.