Open Questions on Gestational Diabetes Mellitus in Twin Pregnancies

Abstract

Abstract: The concurrent increase in prevalence of Gestational Diabetes Mellitus (GDM) and twin pregnancy over recent decades, in combination with the shared risk factors, has led to speculation that multiples are a risk factor for GDM and that GDM may contribute to twin complications. A small number of heterogeneous studies investigating the impact of GDM in twin pregnancies have led to conflicting conclusions. In comparison to singleton pregnancies, multiple pregnancies have different physiology, requiring increased caloric intake, with a low risk for macrosomia and a high risk for fetal growth restriction. However, in twin pregnancies methods of GDM screening, thresholds for diagnosis and treatment, as well as glycaemic control targets, have been predominantly extrapolated from singletons. The present review provides a comprehensive, critical overview of current evidence on GDM in twin pregnancies with an emphasis on prevalence, methods of screening, thresholds for diagnosis, risk of maternal and feto-neonatal complications and the impact of treatment on perinatal outcomes.