Selective versus universal screening for gestational diabetes mellitus: an evaluation of predictive risk factors.

Abstract

To assess whether selective screening for gestational diabetes mellitus (GDM) on the basis of risk-factor assessment is a practicable alternative to universal screening. Case-control study. A 212-bed regional specialist hospital in Melbourne, providing services in obstetrics and gynaecology, paediatrics, geriatrics and rehabilitation. 6,032 women who gave birth at the hospital, May 1996 to August 1997 and November 1997 to August 1998; all were screened for GDM, and 313 were diagnosed with the condition. Odds ratios (ORs) for risk factors (age, obesity, family history of diabetes mellitus and high-risk racial heritage) in women with GDM compared to those without GDM; proportion of women with GDM whose diagnosis would have been missed by selective screening. ORs were 1.9 for age > or = 25 years (95% CI, 1.3-2.7), 2.3 for body mass index > or = 27kg/m2 (95% CI, 1.6-3.3), 2.5 for high-risk racial heritage (95% CI, 2.0-3.2), and 7.1 for family history of diabetes mellitus (95% CI, 5.6-8.9). Other proposed criteria (previous GDM and glycosuria) added no further diagnostic power. Selective screening using the above four criteria would have missed two of 313 cases (0.6%) and could have saved screening up to 1,025 women without GDM (17% of all women). Selective screening for GDM based on prior risk assessment can reduce the need for testing, with negligible loss of diagnostic efficiency.