Optimal delivery time for patients with diet-controlled gestational diabetes mellitus: a single-center real-world study.

BACKGROUND: To determine the optimal delivery time for women with diet-controlled gestational diabetes mellitus by comparing differences in adverse maternal-fetal outcome and cesarean section rates. METHODS: This real-world retrospective study included 1,050 patients with diet-controlled gestational diabetes mellitus who delivered at 35-42 weeks' gestation. Data on patient characteristics, maternal-fetal outcomes, and cesarean section rate based on fetal gestational age were collected and analyzed. Differences between deliveries with and without iatrogenic intervention were also analyzed. RESULTS: The cesarean section rate at ≥ 41 weeks' gestation was significantly higher than that at 39-39 + 6 weeks (56% vs. 39%, p = 0.031). There were no significant differences in multiple adverse maternal or neonatal outcomes at delivery before and after 39 weeks. Vaginal delivery rates were increased significantly at 39-39 + 6 weeks due to iatrogenic intervention (p = 0.005) and 40-40 + 6 weeks (p = 0.003) in patients without and with spontaneous uterine contractions, respectively. CONCLUSIONS: It's recommended that optimal delivery time for patients with diet-controlled gestational diabetes mellitus should be between 39- and 40 + 6 weeks' gestation. Patients who have Bishop scores higher than 4 can undergo iatrogenic intervention at 39-39 + 6 weeks. However iatrogenic interventions are not recommended for patients with low Bishop scores.