Effect of subsequent pregnancies on the risk of developing diabetes following a first pregnancy complicated by gestational diabetes: a population-based study

Diabet. Med. 28, 287–292 (2011) Aims Women with gestational diabetes mellitus have a high risk of developing Type 2 diabetes, secondary to post‐partum progression of the chronic pancreatic ß‐cell defect that underlies their presenting with dysglycaemia in pregnancy. Insulin‐sensitizing therapy can decrease this risk of Type 2 diabetes, partly by offloading the secretory demand placed on the ß‐cells. Conversely, however, it is not known whether the considerable secretory demands posed by the physiologic insulin resistance of a subsequent pregnancy could accelerate the progression to Type 2 diabetes. Thus, we sought to determine whether subsequent pregnancies are associated with the risk of developing diabetes following gestational diabetes. Methods Using a population‐based administrative database, we identified all women in Ontario, Canada, whose first pregnancy was between April 2000 and March 2007 and was complicated by gestational diabetes (n = 16 817). This cohort was followed for a median 4.5 years for subsequent pregnancies and the development of diabetes. Results During follow‐up, 2731 women (16.2%) developed diabetes. Gestational diabetes recurred in 41.5% of subsequent pregnancies. Interestingly, after covariate adjustment, a subsequent pregnancy was associated with a reduced risk of diabetes (adjusted hazard ratio (HR) = 0.68, 95%CI 0.60–0.76; P