We examined the pregnancy outcome of 112 women classified as minor degrees of glucose intolerance (MDGI) in pregnancy in a screening program based on Carpenter and Coustan's criteria. The MDGI group comprised 49 women with abnormal oral glucose challenge test (OGCT) followed by normal OGTT (group A), and 63 with "borderline" OGTT (1 abnormal value, group B). No treatment was offered to 88 MDGI women, while 26 received dietary advice and metabolic monitoring. A control group was constituted from 112 age- and BMI-matched negative screenees. Similar rates of cesarean sections and macrosomia, but higher rate of large for gestational age (LGA) babies (25.9% vs 14.3%) were found in MDGI, without difference between groups A and B. When comparing treated and untreated MDGI, lower LGA incidence (11.5% vs 30.2%) and no macrosomia were found in the former. In conclusion, untreated MDGI may present excessive fetal growth, which can be normalized by dietary treatment and metabolic monitoring.