Pregnancy, Oral Contraceptives, Hormone Replacement Therapy As Risk Factors For Stroke

Speaking on stroke prevention in the `90s, Dr. Steven Kittner,associate professor of neurology at the medical school in Baltimore,presented data from observational studies indicating a 28-foldincreased risk of intracerebral hemorrhage and a nine-fold increase inrisk of cerebral infarction in women during the six weeks afterdelivery.

Pregnancy itself is associated with no increased risk of cerebralinfarction and only a modestly increased risk of intracerebralhemorrhage, Kittner said.

Oral contraceptives seem to cause a dose-associated increased risk ofstroke, said Kittner. "Current research supports the accepted practiceof restricting the use of oral contraceptives in women who smokecigarettes, have a history of hypertension or other risk factors forvascular disease," he said.

The relationship between postmenopausal estrogen replacement therapyand stroke remains less clear, the neurologist said. One large studyshowed a significantly increased risk of stroke both among womentaking estrogen alone and those taking combination hormone replacementtherapy of estrogen and progestin. But another study showed asignificantly reduced risk of stroke in women taking combinationhormone replacement therapy.

Several large clinical trials now under way should provide moredefinitive data, but for now, "there still are only two wellestablished indications for hormone replacement therapy, relief ofmenopausal symptoms and prevention of osteoporosis," Kittner said. "Many uncertainties persist regarding the risk of combinedestrogen-progestin therapy, and the risks/benefits need to be weighedin each individual case.