If pieces of my placenta are left in my uterus after delivery, will it cause me to bleed?

You mentioned that your sister had a baby a couple of weeks ago, and has some concerns about some retained placental fragments. The biggest risk for postpartum hemorrhage exists in the first hour after delivery. And the risk goes down as each hour passes, but it actually does still exist for up to 3 months after the baby is born. In the hours following delivery, the reason for hemorrhage is most commonly uterine atony, which is basically a uterus that doesn't want to do it's job. It's tired and plum-tuckered. After a baby is born, the uterus' job is not done. It contracted all during labor to get the baby out, but as soon as the baby is out, it needs to clamp down really tightly over all the vessels that were feeding the baby. And it's like a tourniquet, and this helps to control bleeding. If this process doesn't happen, then the mother will hemorrhage. So this is the first thing we always consider if the mother is bleeding too much after having a baby.

If a mother's bleeding is prolonged, meaning after 6 weeks, she still hasn't stopped bleeding, or it starts and then stops again, and this whole thing is happening down the road, like weeks later, one of the things we think about is a retained placental fragment. If all of the placental pieces aren't expelled after delivery, and even a small piece is retained, then it can prevent the uterus from cramping down, and this can lead to bleeding problems down the road. But the bleeding problems usually aren't as catastrophic as they are right after delivery. So if your sister has noticed that her bleeding picks up after having previously slowed down, or if her bleeding persists much past 6 weeks, then she should talk with her doctor. And after asking her more specific questions, they'll be able to determine if further investigation or treatment is necessary in her situation. Good luck to both of you, and if either of you have any other questions for me in the future, feel free to ask them on our Facebook page at   / intermountainmoms  , and recommend us to your friends and family too.