Early gestational diabetes treatment modest at best in preventing adverse neonatal outcomes

Treatment of gestational diabetes before 20 weeks’ gestation appears to lead to a modestly lower incidence of a composite of adverse neonatal outcomes as compared with no-immediate treatment, with no substantial differences noted for pregnancy-related hypertension or neonatal lean body mass, as reported in a study.

The study included 802 women between 4 weeks and 19 weeks and 6 days of gestation who had gestational diabetes and a risk factor for hyperglycaemia. These women were randomly assigned to receive immediate treatment for gestational diabetes (n=406) or deferred or no treatment (control, n=396). All participants underwent a repeat oral glucose-tolerance test [OGTT] at 24 to 28 weeks of gestation.

The primary outcomes were a composite of adverse neonatal outcomes (birth at <37 weeks of gestation, birth trauma, birth weight of ≥4,500 g, respiratory distress, phototherapy, stillbirth or neonatal death, or shoulder dystocia), pregnancy-related hypertension (pre-eclampsia, eclampsia, or gestational hypertension), and neonatal lean body mass.

At a mean gestation of 15.6 weeks, the women underwent their initial OGTT. A lower proportion of women in the immediate-treatment group than in the control group had an adverse neonatal outcome event (24.9 percent vs 30.5 percent; adjusted risk difference, −5.6 percentage points, 95 percent confidence interval [CI], −10.1 to −1.2).

Meanwhile, there was no significant between-group difference in the other two outcomes. Pregnancy-related hypertension occurred in 10.6 percent of women in the immediate-treatment group and in 9.9 percent of those in the control group, with an adjusted risk difference of 0.7 percentage points (95 percent CI, −1.6 to 2.9).

The mean neonatal lean body mass was 2.86 kg in the immediate-treatment group and 2.91 kg in the control group, with adjusted mean difference of −0.04 kg (95 percent CI, −0.09 to 0.02).

The frequency of serious adverse events associated with screening and treatment was similar between the two groups.