The relationship among distribution of pathological values at the Oral Glucose Tolerance Test (OGTT), metabolic risk factors and pregnancy outcomes in women with Gestational Diabetes (GDM), has not been clearly identified. We retrospectively compared metabolic and therapeutic parameters, maternal-fetal outcomes and post-partum OGTTs, with respect to the number and distribution of altered values of diagnostic OGTT in pregnancy. Secondly, we assessed whether insulin therapy predictive factors were identifiable. This analysis included 602 pregnant women with GDM, followed in Diabetes and Pregnancy Unit of Perugia Hospital from diagnosis to childbirth. All women were diagnosed diabetic upon 75g OGTT, according IADPSG criteria. Women were divided into 3 groups, respect to distribution of diagnostic blood glucose (BG) values at OGTT: Group 1: only fasting BG (OGTT0h); Group 2: 1 and/or 2h (OGTT1-2h); Group 3: both fasting and 1 h and/or 2h (OGTT0+1-2h) BG. Pregnant women with fasting hyperglycemia at OGTT (Groups 1 and 3) had similar metabolic characteristics (weight, prevalence of obesity, gestational weight gain, HbA1c), a greater need for insulin therapy, and a higher risk of impaired glucose tolerance persistence after childbirth, as compared to Group 2. No significant differences were observed in terms of maternal and neonatal outcomes (p > 0.05), except for a greater prevalence of caesarean sections in Group 3. The metabolic characteristics of GDM women are mirrored by OGTT values at diagnosis, but are not associated with adverse pregnancy outcomes. Intensive management and a tailored treatment of GDM improve maternal-neonatal outcomes, regardless of diagnostic values distribution and pre-gestational metabolic characteristics.