Oxytocin is a uterotonic medication that stimulates uterine contractions and reduces bleeding. It is the most effective intervention for preventing and treating postpartum hemorrhage caused by uterine atony.

Uterine massage can also help to improve uterine tone and expel clots.

Choice B) Administering magnesium sulfate is wrong because magnesium sulfate is used to prevent seizures in patients with preeclampsia or eclampsia, not to control bleeding.

Choice C) Administering heparin is wrong because heparin is an anticoagulant that prevents blood clotting.

It is used to treat or prevent thromboembolic disorders, not to stop bleeding.

Choice D) Administering insulin is wrong because insulin is used to lower blood glucose levels in patients with diabetes mellitus, not to manage hemorrhage.

Normal blood loss after vaginal delivery is less than 500 mL and after cesarean delivery is less than 1000 mL.

Postpartum hemorrhage is defined as blood loss of at least 100