Correlation between first- and early third-trimester glucose screening test results.
One hundred twenty-four normal gravidas had paired first- and early third-trimester (26-32 weeks) 1-hour oral glucose screening tests performed. First-trimester oral glucose screening test values correlated significantly with third-trimester glucose screening test results for the entire population, for whites and non-whites, and for normal-weight and obese patients. First-trimester oral glucose screening test values at or below 110 mg/dL were seldom associated with third-trimester oral glucose screening test results at or above 135 mg/dL and were not associated with abnormal 3-hour glucose tolerance test (GTT) results. Nine of the gravidas (7.3%) were diagnosed with gestational diabetes mellitus during the third trimester, all of whom had first-trimester glucose screening test results above 110 mg/dL. The difference in incidence of gestational diabetes mellitus between gravidas having first-trimester glucose screening test results at or below 110 mg/dL (0%) and those having values above 110 mg/dL (16.4%) was highly significant (P less than .0001). For patients with first-trimester glucose screening test values at or below 110 mg/dL, third-trimester glucose screening may be unnecessary. In contrast, for gravidas having first-trimester glucose screening test results at or above 135 mg/dL, there is a high positive predictive value for elevated repeat glucose screening test results during the early third trimester. Patients having elevated first-trimester glucose screening values at or above 140 mg/dL are at particularly high risk for elevated glucose screening test results later in pregnancy and should forego repeat 1-hour third-trimester glucose screening in favor of a direct third-trimester 3-hour GTT.
Nahum
G G
GG
Department of Obstetrics and Gynecology, Kaiser Foundation Hospital, Los Angeles, California.
Huffaker
B J
BJ
D000328:Adult; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D015141:Los Angeles / Q000453:epidemiology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third; D011254:Pregnancy in Diabetics / Q000175:diagnosis* / Q000208:ethnology