Early gestational diabetes screening in obese women does not reduce perinatal outcomes

Early screening for gestational diabetes does not improve the composite perinatal outcomes in obese women, reveals a study.

A total of 962 obese women (body mass index ≥30 kg/m²) at two tertiary care centres in the United States were randomized to either early gestational diabetes screening (14–20 weeks; n=459; 49.8 percent) or to routine screening (24–28 weeks; n=463; 50.2 percent).

The authors screened women using a 50-g, 1-hour glucose challenge test, followed by a 100-g, 3-hour glucose tolerance test if the initial screen was ≥135 mg/dL, and diagnosed gestational diabetes based on the Carpenter–Coustan criteria. Those who were not diagnosed at 14–20 weeks were rescreened at 24–28 weeks. Women with pre-existing diabetes, major medical illness, had bariatric surgery or prior caesarean delivery were excluded.

Baseline characteristics were balanced between the two groups. Sixty-nine women (15.0 percent, 95 percent confidence interval [CI], 11.9–18.6) in the early screening group were diagnosed with gestational diabetes: 29 (6.3 percent, 95 percent CI, 4.3–8.9) at <20 weeks and 40  (8.7 percent, 95 percent CI, 6.3–11.7) at >24 weeks.

Fifty-six women (12.1 percent, 95 percent CI, 9.3–15.4) who underwent routine screening had gestational diabetes. Of note, early screening failed to reduce the incidence of the composite of macrosomia, primary caesarean delivery, hypertensive disease of pregnancy, shoulder dystocia, neonatal hyperbilirubinaemia and neonatal hypoglycaemia (56.9 percent in the early screen vs 50.8 percent in the routine screen; p=0.07; relative risk, 1.12, 95 percent CI, 0.99–1.26).

In 2013, the American College of Obstetricians and Gynecologists recommended early screening for gestational diabetes in obese women, the authors noted.