Gestational weight loss relative to prepregnancy weight in women with gestational diabetes: impact on maternal and neonatal outcomes.

PURPOSE: Gestational weight loss (GWL) of overweight or obese women with gestational diabetes (GDM) during the third trimester has been associated with lower risk of macrosomia, caesarean delivery (CS) or neonatal intensive care unit (NICU) admission but with higher risk of preterm delivery (PTD) and small-for-gestational-age (SGA). We studied the association between GWL during the whole pregnancy and perinatal outcomes. METHODS: We conducted a retrospective study of the Portuguese national GDM database including all women with singleton pregnancies diagnosed by 24-28 week OGTT (oral glucose tolerance test) who delivered a liveborn infant and had recorded perinatal outcomes and gestational weight change. GWL was defined as weight loss between the maternal weight at delivery and pregestational weight. RESULTS: Among 7768 women, 180 (2.3%) had GWL; they had higher BMI, more frequent family history of type 2 diabetes, previous GDM, chronic hypertension, multiparity, higher fasting OGTT glucose and more frequent metformin treatment than women without GWL. GWL was associated with higher odds of PTD (OR 2.35, 95%CI 1.40-3.97, p- value = 0.001) and SGA (2.71, 1.70-4.33, p-value < 0.001) and lower odds of CS (0.62, 0.44-0.88, p-value = 0.006) and LGA (0.40, 0.22-0.70, p-value = 0.002), with non significant associations for HDP, NH, RDS and NICU admission. CONCLUSION: GWL was uncommon among women with GDM and was associated with over 2.3-fold higher risk of PTD, 2.7-fold higher risk of SGA newborns, and a 48% lower risk of CS and 60% lower risk of LGA infants.