Parity, coronary heart disease and mortality in the old order Amish

Prior data on the association between parity and mortality are limited by the presence of sociodemographic confounders including cultural norms of parity. Our objective was to determine the association between parity and mortality in the Amish, a socioeconomically homogenous group with large numbers of children per family.

We conducted a population-based cohort study among 518 Old Order Amish women enrolled in a cardiovascular awareness program. The mean length of follow-up for mortality was 13.52 years. We determined the adjusted associations between parity and obesity, prevalent coronary heart disease and mortality.

The mean number of total births per woman was 6.7 ± 3.6 with a mode of 8. No significant association was observed between parity and all-cause mortality when adjusted for age (HR 1.00 per additional birth; 95% CI 0.96-1.05; p = 0.85) or in multivariate analysis (HR 1.00, 95% CI 0.95-1.05; p = 0.95). There was also no association of parity in age- or multivariable adjusted models with prevalent diabetes, hypertension or coronary heart disease. Despite the lack of effect of parity on mortality, a significant association of ten or more births was observed with higher body mass index (BMI) compared to the referent group of 8-9 total births.

In a highly homogeneous population with high rates of parity, no association between overall mortality and parity was observed. Ten or more births were significantly associated with a higher BMI but not with overall mortality.