Universal vs. risk factor-based screening for gestational diabetes mellitus: detection rates, gestation at diagnosis and outcome

Aims Gestational diabetes mellitus (GDM) is associated with adverse maternal and fetal outcome. Screening for GDM is therefore recommended bur the best screening method remains controversial. This prospective, randomized study compared a risk factor-based screening programme with a universally based one. Methods Subjects were randomized at booking to one of two groups: the risk factor group had a 3-h 100-g oral glucose tolerance test (OGTT) at 32 weeks if any risk factor for GDM was present; the universal group had a 50-g glucose challenge test performed and if their plasma glucose at 1 h was greater than or equal to 7.8 mmol/l, a formal 3-h 100-g OGTT was then performed. Results Universal screening detected a prevalence of GDM of 2.7%, significantly more than the 1.45% detested in the risk factor screened group (P < 0.03). Universal screening facilitated earlier diagnosis than risk factor screening - mean gestation 30 +/- 2.6 weeks vs. 33 +/- 3.7 weeks (P < 0.05). A higher rate of spontaneous vaginal delivery at term, and lower rates of macrosomia, Caesarean section, prematurity, pre-eclampsia and admission to neonatal intensive care unit were observed in the universally screened, early diagnosis group. Conclusions Universal screening for GDM. is superior to risk factor based screening - detecting more cases, facilitating early diagnosis and is associated with improved pregnancy outcome.