Objectives: To assess the prevalence and association of frequently used scr
eening risk factors for gestational diabetes mellitus (GDM) and to compare
the validity and cost of universal screening with risk factor screening. Me
thod: A cross-sectional survey of 768 pregnant women at greater than or equ
al to 24 weeks' gestation who were attending the antenatal clinic at the Ho
spital Universiti Kebangsaan Malaysia (HUKM) was made. Risk factors were de
termined using a questionnaire. An abnormal oral glucose tolerance test was
defined as a 2-h post-prandial blood sugar level of greater than or equal
to 7.8 mmol/l. Results: A total of 191 pregnant mothers (24.9%) had GDM. Th
e most commonly identified screening factors were positive family history o
f diabetes mellitus (31.4%), history of spontaneous abortion (17.8%), vagin
al discharge and pruritis vulvae in current pregnancy (16.0%), and maternal
age greater than 35 years (14.7%). Five hundred and thirteen mothers (66.8
%) had at least one risk factor. All screening risk factors, except past hi
story of diabetes mellitus in previous pregnancy and maternal age, were not
significantly associated with abnormal glucose tolerance (GT). Risk factor
screening gave a sensitivity of 72.2% and a specificity of 35.0%. Universa
l screening would cost RM 12.06 while traditional risk factor screening wou
ld cost RM 11.15 per identified case and will have missed 53 of the 191 cas
es. Conclusions: Risk factor screening scored poorly in predicting GDM. Cos
t analysis of universal compared with traditional risk factor screening sho
wed a negligible difference. Thus universal screening appears to be the mos
t reliable method of diagnosing GDM. (C) 2001 International Federation of G
ynecology and Obstetrics. All rights reserved.