The third stage of labour involves the delivery of the placenta after childbirth. It typically lasts 10-20 minutes and involves signs of placental separation like lengthening of the umbilical cord. Controlled cord traction is the standard technique for placental delivery but if not successful within 20 minutes, manual removal is required. Complications can include postpartum hemorrhage, retained placenta, and inversion of the uterus. Postpartum hemorrhage is the leading cause of maternal mortality and morbidity, with uterine atony being the most common cause. Management involves uterine massage, oxytocic drugs, bladder catheterization, and other measures, with blood transfusion and surgery as a last resort.