Australia: Gestational Diabetes Study

Treating gestational diabetes immediately before 20 weeks' gestation improved neonatal outcomes, the TOBOGM randomized trial has revealed.

Immediate treatment significantly reduced the composite incidence of adverse neonatal outcomes, including:

• Shoulder dystocia
• Stillbirth or neonatal death
• Phototherapy
• Respiratory distress
• High birth weight
• Birth trauma
• Preterm birth

The rate was reduced to 24.9% compared with 30.5% in those whose treatment depended on confirmation as usual after a repeat oral glucose tolerance test (OGTT) at 24 to 28 weeks of gestation. However, no material differences were observed for neonatal lean body mass or pregnancy-related hypertension.

The findings appeared in the New England Journal of Medicine. They were presented at the International DIP Symposium on Diabetes, Hypertension, Metabolic Syndrome & Pregnancy: Innovative Approaches in Maternal Offspring Health in Thessaloniki, Greece.

David Simmons, Western Sydney University, Australia, and colleagues aimed to determine whether treatment of gestational diabetes before 20 weeks' gestation improves infant and maternal health.

The study involved women between 4 weeks' and 19 weeks six days' gestation who had a risk factor for hyperglycemia, and gestational diabetes diagnosis was included. Eight hundred two individuals were randomly assigned in a ratio of 1:1 to receive immediate treatment for gestational diabetes or no treatment or deferred, depending on the findings of a repeat OGTT at 24 to 28 weeks gestation.

Primary Outcomes

• Composite of adverse neonatal outcomes (birth at <37 weeks' gestation, birth weight of ≥4500 g, birth trauma, phototherapy, respiratory distress, shoulder dystocia, neonatal death or stillbirth)
• Neonatal lean body mass
• Pregnancy-related hypertension (gestational hypertension, eclampsia, or preeclampsia)

Study Findings

Eight hundred two women underwent randomization; 406 were allocated to the immediate-treatment group and 396 to the control group; follow-up data were available for 793 women. At a mean gestation of 15.6 weeks, an initial OGTT was performed.

• An adverse neonatal outcome event occurred in 24.9% of women in the immediate-treatment group and 30.5% in the control group (adjusted risk difference, −5.6 percentage points).
• Pregnancy-related hypertension occurred in 10.6% of women in the immediate-treatment group and 9.9% in the control group (adjusted risk difference, 0.7 percentage points).
• In the immediate-treatment group, the mean neonatal lean body mass was 2.86 g; in the control group, it was 2.91 g (adjusted mean difference, −0.04 g).
• No between-group differences were observed concerning severe adverse events associated with treatment and screening.

"Gestational diabetes' immediate treatment before 20 weeks' gestation versus no immediate treatment led to a modestly lower incidence of a composite of adverse neonatal outcomes," the researchers conclude. "No material differences were seen for neonatal lean body mass or pregnancy-related hypertension."

Reference

The study titled "Treatment of Gestational Diabetes Mellitus Diagnosed Early in Pregnancy" was published in the New England Journal of Medicine. DOI: 10.1056/NEJMoa2214956