Abstract
PURPOSE: This study aimed to examine the effects of gestational diabetes mellitus (GDM) on the risk of pregnancy complications in twin pregnancies and to investigate the relationship between glycemic levels and the risk of preeclampsia (PE) and abnormal fetal growth. PATIENTS AND METHODS: A retrospective cohort study of 736 twin pregnancies was conducted at a tertiary hospital. Propensity score matching and multivariable logistic models were utilized to compare maternal and neonatal outcomes between twin pregnancies with GDM and those without GDM. Multivariable logistic regressions were performed to address the intertwin correlation between glycemic levels and the primary outcomes. RESULTS: There was no significant difference in the risk of PE between non-GDM and GDM pregnancies (OR, 0.70; 95% CI: 0.38-1.27; P = 0.238). No statistically significant differences were observed in the prevalence of small for gestational age and large for gestational age between the study groups. A comparative analysis of twin pregnancies affected by PE and GDM versus those without GDM revealed that the former group exhibited similar maternal and neonatal outcome risks. Women with fasting blood glucose levels from 5.1 mmol/L (92mg/dL) to less than 5.3 mmol/L (95.6mg/dL) had a significantly higher risk of PE compared with women without GDM (OR, 2.90; 95% CI: 1.12-7.51; P = 0.028). In subgroups of glycosylated hemoglobin (HbA1c), HbA1c ≥ 5.5% had the highest risk of PE in the second and third trimesters compared with women without GDM (OR, 4.90; 95% CI: 1.00-24.12; P = 0.05). CONCLUSION: The risk of PE was not increased in twin pregnancies complicated with GDM, but significantly increased in women with an HbA1c ≥5.5%. No significant associations were observed between the co-occurrence of GDM and PE and the incidence of pregnancy complications in twin pregnancies. Strict glycemic control may decrease the risk of PE in twin pregnancies with GDM.