Association between number of abnormal glucose values and severity of fasting plasma glucose in IADPSG criteria and maternal outcomes in women with gestational diabetes mellitus.

Aims: The International Association for Diabetes in Pregnancy Study Group (IADPSG) criteria recommend a single-step diagnostic oral glucose tolerance test (OGTT) for diagnosis of gestational diabetes mellitus (GDM). The aim of this study was to examine the association between the number of abnormal glucose values and levels of FPG with pregnancy outcomes.

Methods: Pregnant women (n=1,044) were screened for GDM at maternity centers in South India using IADPSG criteria. OGTTs were classified based on the number of abnormal glucose values (any one value or more than one value high) and fasting plasma glucose (FPG) values (<92mg/dl,92-100mg/dl,>100mg/dl) and correlated with pregnancy outcomes. Odds ratio were adjusted for age, BMI, gestational week at diagnosis, family history of diabetes, previous history of GDM, gestational week at delivery and birth weight. For macrosomia and large for gestation age, birth weight was excluded from the model.

Results: Risk of caesarean section was significantly higher in women with any one abnormal glucose value (OR: 1.49; 95%CI: 1.07-2.09). This further increased in those with >1 value (OR: 1.35; 95%CI: 0.87-2.10), when compared to women with all values normal. Risk of large for gestation age (LGA) was higher in women with FPG 92-100mg/dl (OR: 1.37; 95%CI: 0.80-2.35) and in those with FPG >100mg/dl (OR: 1.87; 95%CI: 1.04-3.35), compared to those with FPG <92mg/dl.

Conclusions: The risk for poor pregnancy outcomes starts in those with one abnormal value in the OGTT or with FPG >92mg/dl but becomes significantly higher in those with higher abnormal values.