Delivery of the placenta is the third stage of labour. It happens after the baby is born.
Discuss the plan with your maternity team
The third stage may be managed actively, with treatment to help the placenta be delivered, or physiologically. Active management reduces the risk of heavy bleeding. The appropriate approach depends on your circumstances and your maternity team’s assessment.
If you plan to retain the placenta, tell the team in advance. Medical care and any necessary examination of the placenta take priority over collection.
Further reading: NHS: stages of labour and birth.