The placenta is a temporary organ that only exists in your uterus during pregnancy. It develops in your uterus 7 to 10 days after conception and attaches to the uterine wall away from your cervix. The placenta continuously grows to support your baby and remains in your uterus until the final stage of childbirth. For a full term birth, it is about 1 pound.
Your baby is connected to the placenta by the umbilical cord. Your developing baby needs nutrients, food, and oxygen. Together, the placenta and umbilical cord pass all these vital resources from you to your baby. If you are expecting twins, your babies either share a placenta, or they can have their own placentas.
Learn about Placenta Complications here