Placental Growth, Fetal Growth and Maternal RhE Genotype

The Rh locus is composed of two genes RhD, which encodes the major D antigen and is present only in Rh-positive genomes, and RhCE, which encodes both the Cc and Ee polypeptides, most likely by alternative splicing events. Several membrane components, including Rh proteins and other glycoproteins recently characterized, are probably different subunits of an oligomeric complex with transport functions in the erythrocyte [3]. In previous papers we have reported an association of maternal RhE phenotype with neonatal macrosomia [1] and with metabolic control [2] in diabetic pregnant women. The recent discoveries on the structure and functions of Rh proteins prompted us to look for possible association of RhE phenotype with placental weight and birth weight in normal pregnancy. 260 Consecutive puerperae along with their newborn babies have been examined in the population of Penne. 295 Diabetic puerperae (including gestational and pre-existing IDDM and NIDDM) from the population of Rome along with their newborn babies have also been considered. Some data on these diabetic women have been reported in previous studies [1,2]. We have now considered also placental weight not examined in our previous reports. Table 1 shows the relationship of maternal RhE phenotype with birth weight and placental weight. In healthy puerperae there is a strong Letter to the Editor