Neonatal hypoglycemia less common with stricter gestational diabetes diagnosis standards

More pregnant Japanese women have been diagnosed with gestational diabetes and fewer births have resulted in neonatal hypoglycemia since Japan adopted new criteria for diagnosing the condition in 2010, according to findings published in the Journal of Diabetes Investigation.

“Previous studies have reported that screening for and treatment of gestational diabetes improves pregnancy outcomes; however, gestational diabetes diagnostic criteria are inconsistent across countries, and it is hoped that an internationally uniform gestational diabetes screening system can be established,” Shigeru Aoki, MD, PhD, of the perinatal center for maternity and neonates at Yokohama City University Medical Center in Japan, and colleagues wrote.

Aoki and colleagues assessed the frequency of gestational diabetes diagnoses and the frequency of complications such as neonatal hypoglycemia, respiratory distress syndrome, large for gestational age, cesarean delivery, operative vaginal delivery, small for gestational age, shoulder dystocia and admission to the neonatal ICU via the medical records of 3,912 women who gave birth before 2010(median gestational age, 32 years) and 4,772 women who gave birth after 2010 (median gestational age, 33 years) when Japan adopted the International Association of Diabetes and Pregnancy Study Groups’ (IADPSG) criteria.

Changing diagnostics

Cutoffs of 100 mg/dL for fasting plasma glucose, 180 mg/dL for 1-hour glucose and 150 mg/dL for 2-hour glucose were set to determine gestational diabetes following a 75 g oral glucose tolerance test before 2010. If a mother met more than one of these, they were diagnosed with gestational diabetes. Cutoffs of 92 mg/dL in FPG, 180 mg/dL in 1-hour glucose and 153 mg/dL in 2-hour glucose were set to determine gestational diabetes after 2010. Mothers who reached one of these were diagnosed with gestational diabetes.

Among those assessed after 2010, 13% were diagnosed with gestational diabetes vs. 2.9% of those who were assessed before 2010 (P < .001). The researchers added that 1.1% of those assessed after 2010 needed insulin compared with 0.5% of those assessed before 2010 (P = .003).

“The introduction of the IADPSG criteria resulted in a major increase in the rate of diagnosis of gestational diabetes,” the researchers wrote.

Effects on complications

Children born to mothers assessed after 2010 were 49% less likely to experience neonatal hypoglycemia (adjusted OR = 0.51; 95% CI, 0.29-0.88) and 22% less likely to require admission to the neonatal ICU (aOR = 0.78; 95% CI, 0.65-0.92) compared with those born to mothers assessed before 2010. Children born to mothers diagnosed with gestational diabetes after 2010 were 70% less likely to require admission to the neonatal ICU compared with children born to mothers diagnosed with gestational diabetes before 2010 (aOR = 0.3; 95% CI, 0.21-0.92). Children born to mothers who were not diagnosed with gestational diabetes after 2010 were 51% less likely to experience neonatal hypoglycemia (aOR = 0.49; 95% CI, 0.27-0.91) and 17% less likely to require admission to the neonatal ICU (aOR = 0.83; 95% CI, 0.69-0.99) compared with children born to mothers who were not diagnosed with gestational diabetes before 2010.

“After the introduction of the IADPSG criteria to diagnose gestational diabetes, the rates of neonatal hypoglycemia and neonatal ICU admission decreased. However, the introduction of the IADPSG criteria resulted in a significant increase in the prevalence of gestational diabetes, and a fourfold increase in the number of pregnant women requiring therapeutic intervention,” the researchers wrote. “Further research is required to determine whether the effects are consistent with these changes and to evaluate the validity of these diagnostic criteria.” – by Phil Neuffer

Disclosures: The authors report no relevant financial disclosures.