Evaluation of oral glucose tolerance test results in pregnancy.

Oral glucose tolerance and insulin response to glucose were analysed in 124 pregnant women during the fourth quartile of pregnancy. Employing different criteria for the detection of glucose intolerance, 9% to 21% of women were abnormal, and using the H index 43% would have been declared "diabetic". There was no evidence of a progressive change in the glucose curve detectable by the H index within the fourth quartile of pregnancy. There was no association between actual or potential fetal morbidity and any of the interpretative criteria employed. It is concluded that the oral glucose tolerance test should be interpreted with caution if non-pregnant criteria of abnormality are employed.