Association of pre-pregnancy BMI and postpartum weight retention with postpartum HbA1c among women with Type 1 diabetes

Aim To examine the association of pre‐pregnancy BMI and postpartum weight retention with postpartum HbA1c levels in women with Type 1 diabetes. Methods We longitudinally evaluated 136 women with Type 1 diabetes who received prenatal, pregnancy, and postpartum care through Joslin Diabetes Center's Diabetes and Pregnancy Program between 2004 and 2009. Weight, BMI and HbA1c concentrations were assessed before the index pregnancy and repeatedly monitored after delivery until 12 months postpartum. We used linear mixed models to assess the association of postpartum HbA1c with pre‐pregnancy BMI and postpartum weight retention. Results The mean HbA1c concentration increased from 49 mmol/mol (6.6%) at 6 weeks postpartum to 58 mmol/mol (7.5%) by 10 months postpartum, a level similar to the mean pre‐pregnancy HbA1c concentration. Postpartum weight retention showed a linearly decreasing trend of 0.06 kg/week (P