THE MODE OF INSERTION OF UMBILICAL-CORD AND VESSELS - ASSOCIATION WITH MATERNAL HEMOGLOBIN GENOTYPE, NEONATAL FACTORS, AND PLACENTAL COMPONENT VOLUMES

We investigated whether variations in mode of attachment of umbilical cords and vessels coincided with differences in maternal haemoglobin g enotype and neonatal factors or placental micro-volumetric composition . The incidence of placentae with marginally inserted cords, or those in which umbilical vessels separated prior to insertion, was not stati stically different in samples from sickle cell patients having haemogl obin-SS and haemoglobin-SC genotypes, as compared with haemoglobin-AA controls. Results obtained from analysis of variance (ANOVA) suggest t hat the mode of insertion (status) of umbilical vessels may have clini cal significance, because it produced differences in the main effects associated with neonatal gestational age, placental weight, and placen tal index. Point counting stereology was employed to estimate the micr oscopic compartment volumes of placentae prior to an assessment of sta tistical association between the data obtained and the status of umbil ical vessels and maternal haemoglobin genotype. Furcate placentae (wit h separated umbilical vessels) had statistically greater than normal v olumes of villi, villous trophoblast, and syncytial knots. We deduce t hat furcate placentae are prone to early delivery, because they are he avier, having more voluminous villi with more trophoblast and syncytia l knots than controls.