<prompt> Most common cause of postpartum haemorrhage PPH isAtonic uterusCervical tearsEpisiotomy woundVaginal tears  <response>: Ans. a Atonic uterus. Ref. Textbook of Obstetrics by Dutta, 3rd ed., 424Most Common Cause Of Primary PPH is atonicity of the uterus 80Most Common Cause Of secondary PPH is retained bits of cotyledon or membrane.RISK FACTORS FOR POSTPARTUM HEMORRHAGE Multiple Gestations Large baby Polyhydramnios Multiparity particularly grand multiparity, more than 5 term pregnancies Prolonged labor uterine inertia Labor augmented with Pitocin General Anesthesia Placenta Previa Abruptio Placentae Magnesium Sulfate infusion 