Screening of gestational diabetes mellitus using fasting plasma glucose before the 24th gestational week in women with different pre-pregnancy body mass index

Abstract

Background: Gestational Diabetes Mellitus (GDM) is usually diagnosed between 24th and 28th gestational week using the 75-g Oral Glucose Tolerance Test (OGTT). It is controversial that if FPG ≥92 mg/dL before 24th gestational week should be intervened or not. The aim of this study was to evaluate the value of FPG to screen GDM before 24th gestational week in women with different pre-pregnancy Body Mass Index (BMI).Methods: This was a hospital based retrospective cohort study done at CHC Balipatna, Khurdha, Odisha. Women who had a singleton live birth between June 20, 2016 and June 30, 2019, resided in Balipatna block area and received prenatal care in the Community Health Centre, were included in this study. Pre-pregnancy BMI, FPG before the 24th gestational week, and one-step GDM screening with 75 g-OGTT at the 24th to 28th gestational weeks were extracted from medical records and analyzed. The pregnant women were classified into four groups based on pre-pregnancy BMI: Group A (underweight), Group B (normal), Group C (overweight) and Group D (obesity). Statistical analysis using independent sample t-test, Analysis of Variance (ANOVA) and Pearson Chi-square test was done.Results: The prevalence of GDM was 20.0% (68/341) in the study population. FPG decreased gradually as the gestational age increased in all pre-pregnancy BMI groups until the 19th gestational week. The incidence of GDM in women with FPG ≥92 mg/dL in the 19th to 24th gestational weeks and pre-pregnancy overweight or obesity was significantly higher than that in women with FPG ≥92 mg/dL and pre-pregnancy BMI <24.0 kg/m2.Conclusions: FPG decreased gradually as the gestational age increased in all pre-pregnancy BMI groups until the 19th gestational week. Pre-pregnancy overweight or obesity was associated with an increased FPG value before the 24th gestational week. FPG ≥92 mg/dL between 19 and 24 gestational weeks should be treated as GDM in women with pre-pregnancy overweight and obesity.