Placental expulsion
（重定向自Afterbirth）
Placental expulsion (also called afterbirth) occurs when the placenta comes out of the birth canal after childbirth. The period from just after the baby is expelled until just after the placenta is expelled is called the third stage of labor.
The third stage of labor can be managed actively with several standard procedures, or it could be managed expectantly (also known as physiological management or passive management), the latter allowing the placenta to be expelled without medical assistance.