Multiple pregnancies and the risk of diabetes mellitus in postmenopausal women

We aimed to investigate whether the number of pregnancies during childbearing age was associated with diabetes in postmenopausal women with no history of gestational diabetes.

Our data source was the continuous National Health and Nutrition Examination Survey 1999 to 2014. We selected 9,138 postmenopausal women over 40 years old who did not have a history of gestational diabetes during pregnancy. Logistic regression analyses were applied for the association of the number of pregnancies with diabetes.

We found women with ≥4 pregnancies had significantly greater fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), 2-hour plasma glucose, and the Homeostatic Model Assessment of Insulin Resistance than those with two to three pregnancies (all P < 0.01). These women also had a significantly higher prevalence of diabetes (28.4% vs 20.7%; P < 0.001). Using the two to three pregnancies group as the reference, we observed a positive association of log-FPG and log-HbA1c with 4 or more pregnancies after adjustment for sociodemographic, lifestyle, and reproductive factors, and body mass index (both P < 0.05). Compared to women with two to three pregnancies, the odds ratios for diabetes were 1.31 (95% confidence interval [CI] 1.01-1.71) for women who never got pregnant and 1.28 (95% CI 1.10-1.48) for those with at least 4 pregnancies after multivariate adjustment.

At least 4 pregnancies through childbearing age may be a potential risk factor for diabetes in postmenopausal women without a history of gestational diabetes.