Association between one abnormal value on 3-hour oral glucose tolerance test and adverse perinatal outcomes in twin gestation

Aim: To investigate whether women with twin gestation and one abnormal value on the diagnostic 3-hour oral glucose tolerance test (OGTT) are at an increased risk of adverse perinatal outcomes. Methods: This was a retrospective multicenter study of women with twin gestation, comparing four groups: (1) normal 50-g screening, (2) normal 100-g 3-hour OGTT, (3) one abnormal value on the 3-hour OGTT, and (4) GDM. Multivariable logistic regressions adjusted for maternal age, gravidity, parity, previous CDs, fertility treatments, smoking, obesity and chorionicity were used. Results: The study included 2,597 women with twin gestations, of which 79.7% had a normal screen, and 6.2% had one abnormal value on the OGTT. In adjusted analyses, women with one abnormal value were found to have higher rates of preterm delivery < 32 weeks, large for gestational age neonates, and composite neonatal morbidity of at least one fetus, however, similar maternal outcomes as those with a normal screen. Conclusion: Our study provides evidence that women with twin gestation and one abnormal value on the 3-hour OGTT are at an increased risk of unfavorable neonatal outcomes. This was confirmed by multivariable logistic regressions. Further research is needed to determine whether interventions such as nutritional counseling, blood glucose monitoring, and treatment with diet and medication would improve perinatal outcomes in this population.