Dilatation of the arteries may be very marked in malignant trophoblastic disease, with a diameter measured on the film as much as 4 mm. instead of the normal nonpregnant uterine artery of 1 mm. or ...

The fetal membranes consist of the chorion, amnion, yolk sac, and allantois. The chorion has three layers: cytotrophoblastic, chorionic connective tissue, and basement membrane. The chorion lies ...

By the end of the first trimester, the arteries open into the spaces between the chorionic villi, delivering the large quantities of maternal blood (and thus nutrients and oxygen) required for the ...

Human chorionic gonadotropin comes from trophoblastic tissue. Trophoblastic tissue is a tissue that develops in the baby during the early days of pregnancy. It later forms part of the placenta.