Correlation between Oral Glucose Tolerance Test Abnormalities and Adverse Pregnancy Outcomes in Gestational Diabetes: A Cross-Sectional Study

Gestational diabetes mellitus (GDM) is associated with maternal and neonatal complications. We aimed to evaluate the relationship between the abnormalities of the oral glucose tolerance test (OGTT) and adverse pregnancy outcomes. This was a retrospective study of GDM patients over a five-year period in a Malaysian tertiary center. The diagnosis of GDM was based on the National Institute for Health and Care Excellence (NICE) guideline. The data on patients' demographics, OGTT results, GDM treatment, and pregnancy outcomes were analyzed. A total of 1105 women were included in the final analysis. The percentage of women with isolated abnormal fasting glucose, isolated two-hour abnormality, and both abnormal values were 4.8%, 87.1%, and 8.1%, respectively. Women with both OGTT abnormalities had a higher risk of preeclampsia (odds ratio (OR) 4.73; 95% confidence interval (CI) 1.45-15.41) and neonatal hypoglycemia (OR 8.78; 95% CI 1.93-39.88). Isolated postprandial abnormality was associated with an 80% lesser risk of neonatal hypoglycemia (OR 0.19; 95% CI 0.04-0.87). Both isolated fasting and multiple OGTT abnormalities were associated with insulin therapy. Multiple OGTT abnormalities were a positive predictor of adverse pregnancy outcomes, while isolated postprandial abnormality was associated with a lesser risk of neonatal complication. Further prospective study is essential to validate these findings.