Introduction: One third of women with gestational diabetes mellitus (GDM) will have diabetes or impaired glucose metabolism at postpartum screening. Objective: Evaluate the percentage of women submitted postpartum screening and associate the result with maternal history. Methods: Retrospective investigation of 1013 pregnancies with GDM (2005-2009). We divided the population into two groups according to the result: normal (group 1) and with diabetes or impaired glucose metabolism (group 2). For both groups we evaluated maternal age, body mass index, weight gain during pregnancy, need for insulin therapy, risk factors for GDM, and newborn weight. Results: Postpartum screening was achieved in 76.8% of women (n=778). The test was considered normal (group 1) in 628 women (80.7%) and modified (group 2) in 150 women (19.3%). Group 2 had older women (median age 34 vs. 33 years; p-value 0.013), higher body mass index (28.5 vs. 25.8kg/cm2; p-value 0.000), more women with diabetes mellitus family history in first degree (50.3% vs. 39.9%; p-value 0.026) and prior personal history of macrosomia (12.1% vs 5.4%; p-value 0.003). Earlier diagnosis of GDM was also made in this group (27 vs. 31 weeks; p-value 0.000) and a higher percentage had made insulin therapy (41% vs. 15%; p-value 0.000), having started earlier (28 vs 30 weeks; p-value 0.010). There was a higher percentage of multiparous pregnant in group 2 (64% vs 49.4%; p-value 0.001) and a larger number of cases of newborns large for gestational age (17.1% vs 8.3%; p-value 0.001). Personal history of GDM and weight gain during pregnancy was similar in both groups. Conclusions: Women who test abnormal in postpartum screening are usually older, heavier, multiparous, with a family related to DM patients and prior personal history of macrosomia. GDM diagnosis is made ealier in pregnancy, more often they need insulin therapy started ealier and there was a higher number of newborns large for gestational age.