Prevalence of Gestational Diabetes Mellitus and associations with adverse pregnancy outcomes in the Faroe Islands: a population-based study

BACKGROUND: Gestational diabetes mellitus (GDM) is associated with adverse maternal and neonatal outcomes. The Faroe Islands follow a selective screening strategy for GDM, and little population-based data exist. This study aimed to determine the prevalence of GDM in the Faroe Islands and its association with perinatal outcomes. METHODS: This nationwide, register-based study included all women with singleton pregnancies from 2021 to 2023 (n = 1,703). Under the national risk-based screening strategy, 1,017 (60%) women underwent a 2-h oral glucose tolerance test (OGTT) using the diagnostic cut-off value of 9.0 mmol/L. Maternal characteristics and selected adverse pregnancy outcomes were examined in relation to GDM. RESULTS: The overall prevalence of GDM was 5.5%. Women with GDM were, in general, older, had more than one previous birth and had higher pre-pregnancy BMI compared to women without GDM. In adjusted logistic regression models, postpartum haemorrhage ≥ 1,000 mL remained significantly associated with GDM. Pre-pregnancy BMI emerged as the strongest predictor of large for gestational age (LGA). CONCLUSIONS: GDM prevalence in the Faroe Islands was 5.5%. Women with GDM had a higher risk of postpartum haemorrhage ≥ 1,000 mL, while associations with elective caesarean section and LGA were attenuated after adjustment. Birthweight outcomes were more strongly related to maternal BMI than to GDM. Continued monitoring of maternal characteristics and pregnancy outcomes is warranted.