Comparison between 100-g glucose tolerance test and two other screening tests for gestational diabetes: combined fasting glucose with risk factors and 50-g glucose tolerance test.
OBJECTIVE
Lack of consensus about which screening tests to use for gestational diabetes mellitus (GDM) and difficulties in performing the gold-standard diagnostic test, the 100-g glucose tolerance test (100-g GTT), justify comparison with alternatives. The aim was to compare this with two other screening tests: combined fasting glucose with risk factors (FG + RF) and 50-g GTT.


METHODS
Prospective longitudinal cohort study in the Hospital School of Universidade Federal de Mato Grosso do Sul.


METHODS
The three tests were performed independently on 341 pregnant women. Sensitivity (S), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (PLR) and negative (NLR) likelihood ratios, and false-positive (FP) and false-negative (FR) rates obtained with FG + RF and 50-g GTT were compared with values from 100-g GTT. The average one-hour post-intake glucose levels (1hPG) with 50-g and 100-g were compared. Students t test was used in the statistical analysis.


RESULTS
FG + RF led more pregnant women (53.9%) to diagnostic confirmation than did 50-g GTT (14.4%). The tests were equivalent for S (86.4 and 76.9%), PPV (98.7 and 98.9%), NLR (0.3 and 0.27) and FR (15.4 and 23.1%). Average 1hPG values were similar: 50-g GTT = 106.8 mg/dl and 100-g GTT = 107.5 mg/dl.


CONCLUSIONS
Diagnostic efficiency with simplicity, practicality and low cost make FG + RF more appropriate for screening for GDM. The equivalence of 1hPG allows a new, cheaper and less uncomfortable protocol to be proposed for screening and diagnosing GDM.
Ayach
Wilson
W
Department of Gynecology and Obstetrics, Hospital Universitário, Universidade Federal de Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil. wilsonayach@uol.com.br
Costa
Roberto Antonio Araújo
RA
Calderon
Iracema de Mattos Paranhos
Ide M
Rudge
Marilza Vieira Cunha
MV
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D016640:Diabetes, Gestational / Q000175:diagnosis* / Q000191:economics; D004812:Epidemiologic Methods; D005215:Fasting / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test / Q000592:standards*; D006801:Humans; D008403:Mass Screening; D009313:National Health Programs / Q000191:economics; D011247:Pregnancy
D001786:Blood Glucose