Background: To describe a reliable method for a general oral glucose tolerance test (OGTT) during pregnancy, to evaluate adherence to the method, and to compare the frequency of reported gestational diabetes mellitus (GDM) and perinatal outcome in affected pregnancies in Skåne, using direct diagnostic OGTT, with those from a comparable area, Halmstad-Ljungby-Växjö (HLV), using random glucose measurements (RGM) to identify women for the OGTT.
Methods: The OGTT program and quality assurance in Skåne is described. Antenatal records on deliveries in May 2003 were scrutinised to ascertain if OGTT had been performed. Frequencies of GDM, prematurity and large for gestational age (LGA) infants were estimated using a population-based perinatal database (PRS).
Results: OGTT was performed in 93% of pregnant women in Skåne. In 2000-2003 GDM frequency in Skåne was twice as high as in HLV (1.9 versus 1%), while the frequency of LGA and prematurity among infants of mothers who were diagnosed with GDM were similar.
Conclusions: Decentralised general OGTT is a reliable and effective method to diagnose GDM. OGTT is twice as sensitive as RGM, and the severity of GDM in the cases identified with OGTT did not differ from the severity of those identified with RGM.