The impact of maternal age,body mass index and maternal weight gain on the glucose challenge test in pregnancy

Objective. The aim of this study was to determine whether maternal age, prepregnancy and mid-trimester body mass index (BMI), or excessive mid-pregnancy weight gain predict abnormal glucose challenge test (GCT) results.

Methods. A retrospective chart review of 75 consecutive singleton pregnancies was performed. Patients were screened at 24–28 weeks of gestation with a 50-g oral GCT. Prepregnancy BMI and pregnancy weight gain up to the time of GCT testing, as well as other demographic data, were recorded. Statistical analysis included regression analysis and Student's t-test, receiver–operator characteristic curve and multivariate logistic regression.

Results. Maternal age and prepregnancy and mid-trimester BMI were significantly higher in women with an abnormal GCT (p < 0.05). A direct correlation was found between these parameters and GCT results (R² = 0.08, R² = 0.102 and R² = 0.116, respectively; p < 0.05). Mid-trimester maternal BMI of ≥30 kg/m² and maternal age ≥32 years are the optimal predictors of abnormal GCT results.

Conclusions. Mid-trimester maternal BMI of ≥30 kg/m² and maternal age ≥32 years are useful predictors of abnormal GCT results. We suggest that these factors should also be considered when selective screening for gestational diabetes mellitus is practiced.