This term fetus is enclosed within its protective membranes. It is gaining nourishment and oxygen from the placenta to which it is attached at the umbilical cord. Metabolic wastes in the fetal blood are removed in the placenta for excretion by the mother. This remarkable arrangement is initiated during early development and allows the embryo to develop and grow in harmony with its environment. It is protected within the fluid filled amniotic cavity. At this time, the amnion is fused with the chorion to form the amniochorionic membrane.
The extra embryonic membranes include:
Chorion - which contributes to the placenta