(anatomy) An organ in most mammals during gestation that supplies food and oxygen to the foetus and passes back waste. It is on wall of the uterus and links to the foetus through the umbilical cord. It is expelled after birth.

plural of placenta

plural of placenta

(gynaecology) A premature separation of the placenta from the uterine wall.

(medicine) Premature detachment of the placenta

plural of placenta praevia

(pathology) A complication of pregnancy in which the placenta is inserted partially or completely in the lower segment of the uterus (above the opening of the cervix).

plural of placenta previa

Alternative form of placenta praevia

(biology) The local fusion of the embryonic stage of an animal to its parent for physiological exchange to promote the growth and development of the young; involves a placenta in non-egglaying mammals.