Effect of varying degrees of "normal" glucose metabolism on maternal and perinatal outcome

Prior studies concerning effects of varying degrees of normal glucose metabolism on pregnancy have reported an increase in the incidence of a variety of pregnancy complications in women with normal oral glucose tolerance test results as the glucose concentration after a standardized meal rose. However, these investigations have neglected to include a control group of women with gestational diabetes for comparison. We theorized that if the adverse outcomes noted were indeed a reflection of glucose concentration, women with gestational diabetes should have an even higher incidence of these complications. Mother and infant charts of 312 consecutive women undergoing an oral glucose tolerance test were reviewed. A glucose challenge test preceded the oral glucose tolerance test in 310. The glucose challenge test value was less than 140 mg/dl in 64 and greater than or equal to 140 mg/dl in 246. There were 63 abnormal oral glucose tolerance test results (2.7% of the population studied). Among all patients, the relationship between glucose challenge test and oral glucose tolerance test values followed a gradient with a progressive rise in mean oral glucose tolerance test values when the glucose challenge test result was greater than or equal to 160 mg/dl. However, the incidence of an abnormal oral glucose tolerance test result did not rise significantly until the glucose challenge test result exceeded 180 mg/dl. A wide variety of outcome parameters were studied; none were related to the glucose challenge test value. Similar analysis of the 2-hour oral glucose tolerance test value revealed an increase in the incidence of nonelective operative deliveries and a decrease in the percentage of infants discharged home with their mother where values were greater than 180 mg/dl. However, when women with gestational diabetes were excluded from analysis, neither the glucose challenge test nor the 2-hour glucose tolerance test measurements were related to adverse outcome. When analysis was limited to women with gestational diabetes, there was no clinically significant relationship between either glucose challenge test or 2-hour glucose tolerance test and the outcome parameters. Finally, when analysis was repeated according to diagnosis, women with gestational diabetes had a significantly higher risk of having nonelective operative delivery, premature delivery, growth-retarded neonate, 1-minute Apgar score less than 7, and neonatal hypoglycemia than women with normal oral glucose tolerance test results.(ABSTRACT TRUNCATED AT 400 WORDS)