Diagnosis of gestational diabetes mellitus: can we avoid the glucose challenge test?

To identify risk factors for gestational diabetes mellitus (GDM) in patients who had either a normal or abnormal glucose tolerance test (GTT) after failing the initial glucose challenge test (GCT). If identified, consideration can be given to circumvent the glucose challenge test for those at risk.

A chart review was performed on 557 patients with abnormal GCT, 278 had an abnormal GTT (cases), and 279 had normal GTT (controls). The following risk factors were extracted: patients' age, body mass index (BMI), ethnicity, selected personal history, and family history. A primary logistic regression and secondary exploratory logistic regression were used to analyze the data.

Of the risk factors reviewed age, BMI, and prior history of GDM were predictive of GDM in the current pregnancy. Age 30-34 had an odds ratio (OR) of 1.95, 95% confidence interval (CI) [1.25,3.05] and over 35 had an OR 3.87 CI [2.12,7.05]. BMI over 30 had an OR 1.95, CI [1.25,3.05] and prior GDM had an OR 2.82 CI [1.55,5.13]. The combination of age and BMI had a significant OR, but not a significant increase over individual risk factors.

Screening by risk factors to circumvent glucose challenge testing may cause unnecessary testing and cost.