50gram oral glucose challenge test combined with risk factor-based screening for gestational diabetes

Eur J Obstet Gynecol Reprod Biol. 2005 Jul 1;121(1):34-7. doi: 10.1016/j.ejogrb.2004.10.008.


Objective: Our aim was to study whether universal screening of all pregnant women by Oral Glucose Challenge Test (OGCT) would identify a higher number of women with Gestational Diabetes (GDM) than risk factor based screening.

Study design: A 50 g OGCT test was performed prospectively in 532 unselected women at 26-28 weeks of gestation. The 1-h venous plasma glucose concentration of >7.3 mmol/l was considered as a positive screening result. Patients with a positive OGCT underwent a 75 g 2-h OGTT, which was used as the actual diagnostic test for GDM. When two or all three of the glucose concentrations in OGTT (measured at fasting state and 1 and 2 h after the 75 g glucose load) were above the 97.5th percentile the patient was considered as having GDM. In addition, women with risk factors for GDM also underwent a 75 g OGTT regardless of the result of the OGCT.

Results: A positive 50 g OGCT was obtained in 123 (23%) of the women. In 15 (12%) of these, a diagnosis of GDM was established by the subsequent OGTT. Out of the 409 remaining women with a normal OGCT, 148 (36%) had risk factors for GDM. An OGTT performed in these patients identified 4 additional women with a GDM. Seventy-nine percent of GDM was thus found with 50g OGCT without regarding risk factors. Forty-seven percent of the women with GDM would have been missed in screening by risk factors only.

Conclusions: In our population 50 g OGCT appears to identify a higher number of GDM than risk factor based screening. Combined with risk factor screening a few more cases of GDM would be found.

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Age Distribution
  • Blood Glucose / analysis*
  • Diabetes, Gestational / diagnosis*
  • Diabetes, Gestational / epidemiology
  • Female
  • Glucose
  • Glucose Tolerance Test
  • Humans
  • Incidence
  • Mass Screening
  • Maternal Age
  • Pregnancy
  • Pregnancy Complications / diagnosis*
  • Pregnancy Complications / epidemiology
  • Pregnancy Trimester, Second
  • Prenatal Care / methods
  • Prospective Studies
  • Risk Assessment
  • Sensitivity and Specificity


  • Blood Glucose
  • Glucose