Diagnosis of Gestational Diabetes Mellitus by 50 grams Glucose Challenge Test

Abstract

Objective:

To find the cut off value  of  50 grams  glucose challenge test (50-g GCT) for  diagnosis  of  gestational diabetes mellitus(GDM)  in relation with risk factors and fasting status of the pregnant women.

Material&methods:All pregnant women at risk for GDM and not related to the fasting  status  were screened  by 50-g GCT . If  ≥ 140 mg/dl , all were continued to 100-g oral glucose tolerance test( 100-g  OGTT)  for diagnosing of GDM  using  the criteria recommended by  NDDG(National Diabetes Data Group)  .The cut off value of 50 grams  glucose challenge test for diagnosis  of GDM  was analyzed  and compared  in relation to the fasting status and risk factors of pregnant women.Results:Data collected from March 2010 to January 2012 showed 614  pregnant women of abnormal GCT . Of  these, 98 lost . 516 of the left continued for diagnosis of GDM using 100-g OGTT. The cut off value of 50-g  GCT  for diagnosis of GDM was ≥ 245 mg/dl (PPV=100%).The  fasting status of the pregnant women lowered the cut off value of 50-g GCT  for diagnosis of GDM to ≥ 190 mg/dl (PPV=100%).Multiple risk factors  lowered the cut off value to ≥ 200mg/dl  for 100% PPV and also obesity and advance maternal age that lowered the value to ≥210 and 225 mg/dl respectively.The pregnant women who had  familial history of diabetes mellitus showed the cut off value of  ≥ 245 mg/dl for diagnosis of GDM.Conclusions:The cut off value of 50-g GCT  for diagnosis of GDM was ≥ 245 mg/dl (PPV=100%).The  fasting status of the pregnant women lowered the cut off value that seem like it is more accurate for  50-g GCT. When concern about risk factor, pregnant women who had multiple risk factors  showed the  lowest  cut off value of  50-g GCT  for diagnosis of GDM.