Afterbirth is the stuff that comes out of a woman's body, or a female animal's body, just after the baby (or the young) has been born. It is the placenta — the organ that fed the baby inside — plus the thin layers that were around the baby. Midwives and animal doctors wait for it and check it is all there, because if a piece stays inside, the mother can become very ill. It is a normal word for hospitals, farms, and biology class: not a rude word, but not a chatting-at-dinner word either. Humans have afterbirth; cows and cats do too. Though actually, in everyday talk many people just say “the placenta” for this whole lot. That is close, but afterbirth is a little wider than that one organ.

胞衣（口語多說「胎盤」，但 afterbirth 還包括包著寶寶的膜）