Tighter glycemic targets were associated with improved maternal and neonatal outcomes in gestational diabetes mellitus (GDM). A single-center, open-label randomized controlled trial published in Diabetes Research and Clinical Practice evaluated whether tighter glucose targets reduce adverse outcomes compared with less strict control in women with GDM.

A total of 650 women with GDM and singleton pregnancies between 12 and 31 weeks’ gestation were randomized to either tighter glycemic targets, defined as fasting plasma glucose <5.1 mmol/L and 1-hour postprandial glucose <7.0 mmol/L, or less stringent targets of fasting <5.3 mmol/L and postprandial <7.8 mmol/L. The primary endpoint was the incidence of large-for-gestational-age (LGA) infants. Secondary outcomes included maternal and neonatal measures, analyzed using an intention-to-treat approach.

Primary outcome data were available for 626 women (96.3%). The incidence of LGA was lower in the tighter target group (19.2%) compared with the less stringent group (26.5%), with an adjusted relative risk (aRR) of 0.61 (95% confidence interval 0.42-0.89; P = 0.010). Cesarean delivery rates were also lower (23% vs 29.9%; aRR 0.63; P = 0.012), along with reduced gestational weight gain (10.1 vs 10.7 kg; P = 0.006).

Insulin therapy was more frequently required in the tighter target group (32.6% vs 21.6%; aRR 1.67; P = 0.005). Rates of serious adverse events and maternal hypoglycemia were low and comparable between groups.

Tighter glycemic targets were associated with lower incidence of LGA, reduced cesarean delivery, and lower gestational weight gain, with increased insulin requirement and no difference in serious adverse outcomes.