Women who have been through the menopause and have experienced at least four pregnancies are more likely to develop type 2 diabetes, research has shown. Data collected from the National Health and Nutrition Examination Survey showed there was a 28 per cent increase in the diabetes risk among women reporting four or more pregnancies when compared to those who became pregnant two or three times. Dr Ningjian Wang, from the department of endocrinology and metabolism at Shanghai Ninth People's Hospital and Shanghai Jiao Tong University School of Medicine, said: "A growing body of evidence suggests that earlier age of menarche, postmenopausal status and both shorter and longer reproductive life spans increase the risk of insulin resistance and [type 2 diabetes]. "Pregnancy has also long been regarded as 'diabetogenic' due to the progressive metabolic alterations during gestation that lead to a state of insulin resistance and compensatory hyperinsulinemia. It has been suggested that additional pregnancies may impair the ability of normal beta-cell function to maintain long-term glucose homeostasis after pregnancy. However, whether subsequent pregnancy is a risk factor for diabetes in later life is still debated." The report involved looking at the health data of more than 9,000 post-menopausal women who had not been diagnosed with gestational diabetes during any of their pregnancies. At the time of collection, all the women had their HbA1c levels measured and undertook a 75g oral glucose tolerance test. They discovered the women who had been pregnant at least four times were more likely to have insulin resistant when compared to those who had only had two or three pregnancies. The research concluded: "Intriguingly, it is worth mentioning that previous studies did not focus on postmenopausal women; thus, women in those studies may have another pregnancy later in life. "However, our study has included all the pregnancies in the women's entire lives, and, accordingly, might offer women in childbearing age more scientific reproductive advice."