Placental villous immaturity is chorionic villous development that is inappropriate for the gestational age. It is associated with diabetes mellitus and fetal death near term, i.e. intrauterine demise close to the normal gestational period. Pathology Immature chorionic villi are larger and have more central blood vessels; thus, the diffusion distance for gas and nutrient exchange is larger and, therefore, placental function is impaired. See also Placenta Placental pathology References External links Health issues in pregnancy