Fasting plasma glucose test at the first prenatal visit as a screen for gestational diabetes

OBJECTIVE: To determine whether the fasting plasma glucose test administered at the first prenatal visit could serve as an efficient screen for gestational diabetes. METHODS: A total of 5557 women not known to have diabetes were offered a fasting plasma glucose test at their first prenatal visit. Results less than 100 mg/dL were blinded. A glucose tolerance test was requested immediately of those whose screening test result was 100-125 mg/dL and of all women not identified as having diabetes by their 23rd gestational week. RESULTS: A total of 4507 women (81%) complied with the protocol. Of the 302 women found to have gestational diabetes, 46 (15%) were detected before 24 weeks. A false-positive rate of 57% was found at a threshold fasting glucose concentration giving a sensitivity of 80% for the detection of gestational diabetes. CONCLUSION: The fasting plasma glucose screening test at the first prenatal visit has good patient compliance. However, its poor specificity (high false-positive rate) makes it an inefficient screening test for gestational diabetes.