This is both a synthesis and a review of the major research findings, with the aim of validating Rudge's group IB. In this group of pregnants, screening for gestational diabetes was positive while the diagnosis was negative (normal 100 g-oral glucose tolerance test 100 g-OGTT). Nonetheless, the variations in glucose levels observed throughout the day, and confirmed by the glycemic profile (GP), characterized diurnal hyperglycemia, which accounts for maternal risk and adverse perinatal outcome. The description of this group is unique for both the establishment of the diagnosis during gestation and the follow-up of both the mother and the infant. These pregnancies have been erroneously classified as "low risk" and have not been diagnosed or treated. The IB group corresponds to 13.8% of the pregnant women screened in our service. This rate, added to the 7% of pregnancies complicated by diabetes, increase the occurrence of hyperglycemic disorders during gestation to up to 20.0%. In Rudge's group IB: a) perinatal mortality rate is 41‰, which is similar to that observed among diabetic pregnant women and 10 times higher than that found among non-diabetics; b) the observed placental abnormalities (both morphological and functional) differed from those seen in non-diabetic and diabetic pregnant women, indicating an adjustment to maintain functional activities that facilitated the passage of glucose to the fetus and explained fetal macrosomia (53.8% in non-treated pregnancies); c) maternal risk for hypertension, obesity and hyperglycemia was high and seemed to reproduce a model of metabolic syndrome, favoring the potential risk for future diabetes; d) 10 years after the index-pregnancy, type 2 diabetes was confirmed in 16.7% of the women in group IB. The authors suggest the development of multicentric studies in order to identify biomarkers specific for Rudge's group IB and establish protocols for the diagnosis of gestational hyperglycemic disorders using the combination GP + 100g-GTT as a standard. This procedure may cause an impact on the morbidity/mortality rate among pregnancies complicated by diurnal hyperglycemia.
Pregnancy; Diabetes mellitus; Hyperglycemia; Prognosis; Public health
