The association between early diagnosis of gestational diabetes and maternal-neonatal outcomes: a secondary analysis of the digest trial

To determine whether early gestational diabetes (GDM) differs from later GDM in maternal characteristics and perinatal outcomes. This is a secondary analysis of an energy-restricted dietary intervention in GDM (DiGest) randomized controlled trial. We compared maternal weight, glycemia, and pregnancy/neonatal outcomes between the early GDM (< 20 weeks, n = 118) and standard GDM diagnosis (21–28 weeks, n = 299) groups. Early GDM was associated with higher antenatal (40 vs. 38 mmol/mol; p = 0.017) and postnatal HbA1c (38 vs. 36 mmol/mol; p = 0.002) and higher risk of diabetes/prediabetes postnatally (19 vs. 6%; p = 0.003). Despite higher medication requirements, perinatal outcomes did not differ. Lower gestational weight gain (2.5 vs. 5.3 kg, p = 0.003) and comparable glycemia at 36 weeks were found. Timing of diagnosis did not impact the effect of the DiGest intervention. Early GDM reflects more severe underlying hyperglycemia, but timely treatment and reduced gestational weight gain can offset adverse perinatal risks.