Glycemic levels with glucose loading test during pregnancy and its association with maternal and perinatal outcomes.

Objective: To evaluate the association between glycemic levels with glucose loading test during pregnancy and maternal and perinatal outcomes.

Methods: Retrospective analysis of 2059 singleton pregnancies screened for gestational diabetes mellitus at Gazi University Faculty of Medicine, Department of Obstetrics and Gynecology between January 2004 and December 2006 was conducted. Sensitivity and specificity of the 50 g glucose loading test was calculated for different cut-off values in our population. Maternal and perinatal outcomes in different groups with different results after screening test were compared.

Results: An increase in cut-off value from 140 to 145 mg/dl seems to be associated with a significant increase in specificity along with a tolerable decrease in sensitivity. A cut-off value of 147.5 mg/dl is associated with a higher specificity and a slightly lower sensitivity. However, the cut-off value 150 mg/dl seems to be associated with a significant decrease in sensitivity. As for the upper limit, a cut-off value of 180 mg/dl is associated with a 90% specificity and a cut-off value of 200 mg/dl is associated with a 99% specificity. A 100% specificity could be reached only after a cut-off value of 221 mg/dl. A GLT value of 180 mg/dl or higher was found to be associated with poor maternal and fetal outcomes, regardless of the result obtained after the diagnostic test.

Conclusion: Results obtained after 50 g GLT should be evaluated separately for each patient and the diagnostic test which is time-consuming, uncomfortable and expensive can be omitted up to a cut-off value of 147.5 mg/dl, especially for those patients with no risk factors. Besides, a GLT value of 180 mg/dl or higher proves the diagnostic test unnecessary as these patients are associated with unfavorable perinatal and fetal outcomes.