Abstract

Objective: To examine the effect of childbearing and maternal breastfeeding on a woman's subsequent risk of developing type 2 diabetes.

Research Design and Methods: Using information on parity, breastfeeding and diabetes collected from 52,731 women recruited into a cohort study, we estimated the risk of type 2 diabetes using multivariate logistic regression.

Results: 3,160 (6.0%) women were classified with type 2 diabetes. Overall, nulliparous and parous women had a similar risk of diabetes. Among parous women, there was a 14% (95%CI 10-18%, p<0.001) reduced likelihood of diabetes per year of breastfeeding. Compared to nulliparous women, parous women who did not breastfeed had a greater risk of diabetes, OR=1.48(95%CI 1.26-1.73, p<0.001); whilst for those breastfeeding for at least 3 months per child, the risk was not significantly increased.

Conclusions: Compared to nulliparous women, childbearing women who do not breastfeed have about a 50% increased risk of type 2 diabetes in later life. Breastfeeding substantially reduces this excess risk.