Relation between low 50-g glucose challenge test results and small-for-gestational-age infants

Aim There is no consensus opinion regarding a possible relation between low 50-g glucose challenge test (GCT) results and small-for-gestational-age infants (SGA). This study aimed to clarify the relation between low 50-g GCT results and SGA, after adjusting for potential confounding factors, using a large clinical dataset. Material and Methods Our retrospective cohort study evaluated the obstetric records of women who delivered at Kofu Municipal Hospital (Japan) between January 2011 and December 2013. The exclusion criteria were gestational diabetes mellitus, diabetes in pregnancy, and GCT results of ≥140 mg/dL. Based on these criteria, we included 1603 women who had undergone a GCT between 24 and 28 weeks of gestation, and divided the subjects into a low-GCT group (≤90 mg/dL) and a non-low-GCT group (91–139 mg/dL). The χ2-test and multivariate logistic regression analysis were used to investigate the association between low GCT results and SGA. Results The mean subject age was 30.4 ± 5.4 years, with 45.1% nulliparity (n = 723) and 1538 (96.0%) term deliveries. The incidence of SGA was 10.7% (172/1603), and 17.9% (287/1603) of the women had low GCT results. Low GCT results were significantly associated with an increased risk of SGA (odds ratio, 1.66; 95% confidence interval, 1.14–2.42), after controlling for maternal age, pre-pregnancy maternal weight, maternal weight gain during pregnancy, and pregnancy-induced hypertension. Conclusion It appears that there is a significant association between low GCT results and SGA. However, further studies are needed to explore the detailed mechanisms of this association.