Impact of Gestational Diabetes Mellitus on Maternal and Neonatal Outcomes in a Tertiary Care Center

Abstract

Background: Gestational diabetes mellitus (GDM) is one of the most prevalent medical complications during pregnancy and is linked to a wide variety of adverse maternal and fetal outcomes, especially in tertiary health care facilities where high-risk pregnancies are concentrated.

Objectives: To find out the prevalence of GDM and to compare maternal and neonatal outcomes of women with and without GDM in a tertiary care obstetric unit.

Methods: A cross-sectional study was performed in 119 pregnant women in Iraq (44 women had been diagnosed with GDM according to the IADPSG criteria and 75 women were not diagnosed with GDM). Data included sociodemographic and obstetric history, screening/diagnostic pathway, glycemic parameters, an expanded set of maternal outcomes, and an expanded set of neonatal outcomes to capture the topic from multiple angles. Independent-samples t-tests were used to compare continuous variables, and chi-square tests were used to compare categorical variables. Two multivariable logistic regression models were used to calculate adjusted odds ratios (aOR) for composite adverse maternal and composite adverse neonatal outcomes; glycemic parameters were compared by glycemic control status and by treatment modality within the GDM group, and Pearson correlation was used to examine the relationship between glycemic parameters and birth weight. The p-value was considered statistically significant if <0.05. Results: GDM prevalence was 37.0% (44/119). Women with GDM had significantly higher pre-pregnancy BMI (29.3 vs 25.6 kg/m2, p<0.001), a higher rate of family history of diabetes (52.3% vs 26.7%, p=0.009), and more previous GDM/macrosomic pregnancies. Pre-eclampsia (25.0% vs 5.3%, OR 5.92, p=0.005), preterm labor (22.7% vs 4.0%, OR 7.06, p=0.004), labor induction (47.7% vs 20.0%, OR 3.65, p=0.003), neonatal hypoglycemia (34.1% vs 8.0%, OR 5.95, p<0.001), and respiratory distress syndrome (20.5% vs 2.7%, OR 9.39, p=0.004) were all significantly more frequent in the GDM group. The composite adverse neonatal outcome (aOR 4.22, 95% CI 1.21–14.68, p=0.024) and composite adverse maternal outcome (aOR 3.09, p=0.055) were significantly associated with GDM on multivariable analysis after adjustment for age, BMI, parity, and either HbA1c or socioeconomic status. In the GDM group, poor glycemic control was significantly associated with macrosomia and neonatal hypoglycemia, and HbA1c (but not single-timepoint glucose values) correlated significantly with birth weight (r=0.36, p=0.016).

In this tertiary care cohort, GDM was significantly linked to a significantly greater burden of adverse maternal and neonatal outcomes, particularly the neonatal pathway, which was most robustly independent of the confounders.