Comparing the course and delivery outcomes of Japanese twin pregnancies with and without gestational diabetes mellitus: a single-center retrospective analysis.

Singleton pregnant women with gestational diabetes mellitus (GDM) are at an increased risk of adverse maternal and neonatal outcomes. Multiple pregnancies are associated with increased risks of perinatal complications; however, the impact of GDM on maternal and neonatal outcomes in multiple pregnancies is unknown, and there are currently few reports on GDM status in twin pregnancies. This study aimed to compare the background and perinatal outcomes between Japanese twin pregnancies with and without GDM at a perinatal center in Japan. Additionally, the clinical course of GDM was investigated. In this retrospective cohort study, women with twin pregnancies underwent GDM screening at Yokohama City University Medical Center from January 2011 to December 2016. Overall, 307 twin pregnancies were divided into GDM (47 cases, 15.3%) and non-GDM (260 cases, 84.7%) groups. GDM-associated pregnancy complications, GDM status, and pregnancy outcomes were ascertained. Women with GDM were older and had a higher pre-pregnancy body mass index than those without GDM. Glycemic control was good in all patients, and there was no difference in delivery outcomes between the two groups. Gestational weight gain was lower in pregnant women with GDM (+8.0 kg) than in those without GDM (+11.8 kg), suggesting the impact of strict nutritional guidance on twin pregnancies with GDM. In conclusion, twin pregnancies with GDM did not have different delivery outcomes compared to those without GDM. To manage twin pregnancies with GDM, this study suggests that it is important to monitor patients' weight and blood glucose levels.