Retained placenta refers to a condition that occurs when all or part of the placenta remains in the uterus after childbirth. There are several synonyms for the term, including incomplete placental expulsion, postpartum retained placental membranes, and retained placental tissue. Other similar terms also include retained afterbirth, retained membranes, and persistent placental retention. This is a serious medical condition that requires prompt diagnosis and treatment to prevent complications such as postpartum hemorrhage, infection, and sepsis. If you suspect you have retained placenta after childbirth, it is critical to seek immediate medical attention.