Use of the 50-g glucose challenge test to predict excess delivery weight

Abstract

Objective: To identify a cut-off value for the 50-g glucose challenge test (GCT) that predicts excess delivery weight.

Methods: A retrospective study was conducted among pregnant women who undertook a 50-g GCT at Hacettepe University Hospital, Ankara, Turkey, between January 1, 2000, and December 31, 2016. Patients with singleton pregnancies who delivered live neonates after 28 weeks of pregnancy were included. Patients were classified according to their 50-g GCT values into group 1 (<7.770 mmol/L); group 2 (7.770 to <8.880 mmol/L, group 3 (8.880-9.990 mmol/L); or group 4 (>9.990 mmol/L). Classification and regression tree data mining was performed to identify the 50-g GCT cut-off value corresponding to a substantial increase in delivery weight.

, results: Median delivery weight were 3100 g in group 1 (n=352), 3200 g in group 2 (n=165), 3720 g in group 3 (n=47), and 3865 g in group 4 (n=20). Gravidity, 50-g GCT value, and pregnancy duration at delivery explained 30.6% of the observed variance in delivery weight. The cut-off required for maternal blood glucose level to predict excessive delivery weight was 8.741 mmol/L.

Conclusion: The 50-g GCT can be used to identify women at risk of delivering offspring with excessive delivery weight.

Keywords: 50-g glucose challenge test; Classification and regression tree; Cut-off value; Excess birthweight; Gestational diabetes mellitus; Pregnancy; Screening.