In the Framingham cohort, the relationships among gravidity, LDL-cholesterol, HDL-cholesterol and total cholesterol were prospectively studied. Each of these serum lipids was tested as a potential mediator of associations between gravidity and various cardiovascular endpoints. In the Hispanic HANES, the associations among parity, gravidity, and lipid levels were examined in cross-sectional data on women of a different ethnic background in whom birth rates tended to be high. Secondary analysis of these two datasets was conducted, carefully considering aspects of the study designs. Bivariate analyses generated mean lipid levels within parity or gravidity groups. HDL, LDL, and total cholesterol were then stratified both by parity and other variables (such as age and smoking status) so that interactions could be considered. Multivariate analyses were used to analyze the effect of parity on lipids and cardiovascular disease events while controlling for a variety of potentially confounding factors (such as body mass index, subscapular/triceps, skinfold ratio, education, income, cigarette smoking, alcohol consumption, oral contraceptive use, estrogen replacement therapy, menopausal status and type of menopause). Interactions were also considered in multivariate models.