Afterbirth

n. placenta expelled after the birth of a baby

The placenta is an ephemeral (temporary) organ present in placental vertebrates, such as some mammals and sharks during gestation (pregnancy). The placenta develops from the same sperm and egg cells that form the fetus, and functions as a fetomaternal organ with two components, the fetal part (Chorion Frondosum) and the maternal part (Decidua Basailis).
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Noun
1. the placenta and fetal membranes that are expelled from the uterus after the baby is born
(hypernym) placenta

(n.)
The placenta and membranes with which the fetus is connected, and which come away after delivery.
  

noun
tissues (including the placenta and umbilical cord) which are present in the uterus during pregnancy and are expelled after the birth of the baby
see also PLACENTA