Reproductive history in women with coronary heart disease. A case-control study.

Reproductive history events may be risk factors for coronary heart disease among women under age 60. In this study, the cases were 169 women under age 60 with a diagnosis of coronary heart disease while residents of Rochester, Minnesota. The first manifestation of coronary heart disease was angina in 95, myocardial infarction in 59, and sudden unexpected death in 15 women. Two age- and sex-matched controls for each case were selected from all registrations for care at the Mayo Clinic in the same year the case was diagnosed. The cases had more of the accepted coronary heart disease risk factors--i.e., hypertension (relative risk = 2.9), smoking (relative risk = 2.4), elevated serum cholesterol (relative risk = 2.6), and diabetes (relative risk = 4.1)--than did controls. In addition, women undergoing artificial menopause and those whose first pregnancy was before age 25 appeared to be at higher risk of coronary heart disease. Use of multivariate analysis to control for known coronary heart disease risk factors resulted in a relative risk of 1.9 for women whose age at first pregnancy was less than 20, and 1.8 for those whose age at first pregnancy was 20-24, as compared with those never pregnant and those whose age at first pregnancy was greater than or equal to 25.