HbA1c as a predictor of postpartum diabetes mellitus after gestational diabetes mellitus.

Abstract Aims Women diagnosed with Gestational Diabetes Mellitus (GDM) should be evaluated postpartum with an Oral Glucose Tolerance Test (OGTT). Nevertheless, women frequently fail to it. We intend to evaluate the performance of third trimester HbA1c in the prediction of postpartum diabetes mellitus (PDM). Methods We conducted a retrospective study of 10245 women with GDM based on the National Registry of GDM. A receiver-operating characteristic (ROC) curve was plotted to evaluate the diagnostic performance of third trimester HbA1c in PDM prediction. Results The mean third trimester HbA1c level was 5.81% (SD 0.69%) in women who developed PDM, 5.40% (SD 0.52%) in women with pre-diabetes and 5.21% (SD 0.43%) in women with normal glucose tolerance in postpartum OGTT, with statistically significant differences (p  Conclusions A third trimester HbA1c level ≥5.4% is associated with a significant higher risk of PDM (p