Positive association between a single abnormal glucose tolerance test value in pregnancy and subsequent abnormal glucose tolerance.

Objective: To study the prevalence of abnormal glucose tolerance among women with a single abnormal glucose tolerance test value in previous pregnancy and identify factors predictive of the later development of abnormal glucose tolerance in this group.

Study Design: In all, 58 women with gestational diabetes, 66 with a single abnormal value in a glucose tolerance test, and 56 control women underwent a 75-g oral glucose tolerance test at a mean of 6.9 years from the index pregnancy.

Results: Abnormal glucose tolerance was present in 34.5% of women with previous gestational diabetes and in 28.7% of women with 1 previous abnormal value, significantly different from the controls (9.7%). Independent risk factors that distinguished the subjects who later developed an abnormal glucose tolerance were prepregnancy BMI, parity > 1, and first-degree relatives affected by diabetes mellitus in the group with gestational diabetes, and prepregnancy BMI, maternal age, (> or = 30 y) and parity > 1 in the group with a single abnormal value. Prepregnancy BMI (> or = 26.9) proved to be the most predictive factor of abnormal glucose tolerance later in life.

Conclusion: Sicilian women with a single abnormal value at the glucose tolerance test in pregnancy have an increased likelihood of developing an abnormal glucose tolerance later in life, similar to gestational diabetes. Prepregnancy BMI was confirmed as the strongest predictive factor in both groups.