Relation between weight gain during pregnancy and postpartum reclassification in gestational diabetes

Gestational diabetes mellitus (GDM) is the most common metabolic disease in pregnancy. It is known that GDM is a precursor to type 2 diabetes (T2D). There is evidence that excessive gestational weight variation (GWV) increases the risk of GDM. So, in this study, we aimed to evaluate the association between GWV and the persistence of diabetes in postpartum reclassification.

A retrospective observational study including pregnant women based on data from the Portuguese National Registry of Gestational Diabetes. Six-to-eight weeks after delivery, all women included underwent a reclassification test. We performed unadjusted and adjusted logistic regression models to evaluate the associations between GWV and diabetes diagnosis at the reclassification test. A subgroup analysis according to the pre-gestational BMI was also performed.

We included 10,389 pregnant women, of which 19.6% had GDM in a previous pregnancy. The median of GWV was 10.0 [6.4, 14.0] kg and was found to be higher for those with a normal BMI. At the DM reclassification test, 1% of the women were diagnosed with T2D. We found a negative association between GWV and postpartum diabetes mellitus (DM). We also present a subgroup analysis, and these associations were only significant for the group with a normal pre-gestational BMI.

Our results showed that women with normal pre-gestational BMI and lower GWV were more likely to have a diagnosis of DM in the postpartum reclassification test. This study helps to fill the gap in the effect of GWG on the persistence of diabetes in postpartum reclassification.