<prompt> Cause of secondary PPH isAtonic uterusRetained placental bitsRuptured uterusCervical laceration  <response>: Causes of secondary PPH: Retained bits of cotyledon or membranes Infection and separation of slough over a deep cervicovaginal laceration Endometritis Hemorrhage from cesarean section wound Withdrawal bleeding following estrogen therapy for suppression of lactation Ref: Dutta Obs 9e pg 392. 