Background: The incidence of pregnancy in advanced age among women is increasing due to availability of assisted reproduction although the complication rates associated with pregnancy are higher. The long-term health consequences in women with pregnancy in advanced age is not known. We determine the effect of pregnancy in advanced age on occurrence of cardiovascular events in a large cohort of post-menopausal women.
Methods: We analyzed the data for 72,221 women aged 50-79 years who were enrolled in the observational arm of the Women's Health Initiative Study. We determined the effect of pregnancy in advanced age (last pregnancy at age≥40 year) on risk of ischemic stroke, hemorrhagic stroke, myocardial infarction, and cardiovascular death over a mean period (± standard deviation [SD]) of 12±1 years using Cox Proportional Hazards analysis after adjusting for potential confounders.
Results: A total of 3306 (4.6%) of the 72,221 participants reported pregnancy in advanced age. Compared with pregnancy in normal age, the rate of ischemic stroke (2.4% versus 3.8%, p<0.0001), hemorrhagic stroke (0.5% versus 1.0%, p<0.0001), myocardial infarction (2.5% versus 3.0%, p<0.0001), and cardiovascular death (2.3% versus 3.9%, p<0.0001) was significantly higher among women with pregnancy in advanced age. In multivariate analysis, women with pregnancy in advanced age were 60% more likely to experience a hemorrhagic stroke (Hazards ratio [HR] 1.6, 95% confidence interval [CI] 1.1-2.4) after adjusting for age, race/ethnicity, congestive heart failure, systolic blood pressure, atrial fibrillation, alcohol use and cigarette smoking. There was no significant difference in the risk of ischemic stroke, myocardial infarction, and cardiovascular death among women with pregnancy in advanced age after adjusting for potential confounders.
Conclusions: Women with pregnancy in advanced age have a higher risk for hemorrhagic stroke in post-menopausal period.