A retained placenta occurs when the placenta, or a portion of it, does not naturally exit the uterus within a specific timeframe after childbirth. This condition is a concern following delivery, as the placenta plays a role in sustaining the pregnancy by providing nutrients and oxygen to the fetus. Understanding when placental delivery deviates from the norm helps in recognizing potential issues. This article explores the frequency of retained placenta, its underlying causes, and its management.
Understanding Retained Placenta
After a baby is born, the uterus continues to contract, which helps the placenta detach from the uterine wall and be expelled. This process, known as the third stage of labor, usually concludes within 30 minutes. If the placenta is not delivered within 30 minutes to an hour after the baby’s birth, it is considered retained.
There are several ways a placenta can be retained. Placenta adherens, the most common type, occurs when the uterine contractions are not strong enough to fully separate and expel the placenta, leaving it loosely attached to the uterine wall. Another type is a trapped placenta, where the placenta detaches from the uterine wall but remains inside the uterus because the cervix closes too quickly, preventing its exit.
A more complex type is placenta accreta spectrum, which occurs when the placenta grows too deeply into the uterine wall, making natural detachment difficult or impossible. This can range from the placenta attaching firmly to the uterine wall (placenta accreta), to penetrating the uterine muscle (placenta increta), or even growing through the uterine wall and impacting other organs (placenta percreta).
How Common is Retained Placenta?
Retained placenta is an uncommon occurrence, affecting approximately 1% to 3% of vaginal deliveries. The incidence can vary slightly depending on the population studied and management practices.
Several factors can increase the likelihood of a retained placenta. A history of a previous retained placenta significantly raises the risk of it happening again. Other risk factors include prolonged labor, particularly an extended first or second stage of labor. Delivering prematurely, especially before 34 weeks of gestation, also increases the risk.
Certain pregnancy complications, such as placenta previa (where the placenta partially or totally covers the cervix) or conditions within the placenta accreta spectrum, are associated with retained placenta. Medical interventions during labor, such as prolonged use of oxytocin to stimulate contractions, can also be a contributing factor. Conditions like uterine atony, where the uterus does not contract adequately after birth, can prevent the placenta from separating. Maternal age over 30 and a stillborn delivery are additional risk factors.
Recognizing Symptoms and Potential Complications
The most evident indication of a retained placenta is its failure to be completely expelled from the uterus within the expected timeframe after childbirth. Other symptoms may develop if parts of the placenta remain inside the body for days or weeks. These can include excessive postpartum bleeding, such as heavy bleeding or the passage of large blood clots.
Other signs include a fever, which may indicate an infection, or a foul-smelling vaginal discharge. Abdominal pain or persistent cramping that does not subside after delivery can also be a symptom.
If not addressed promptly, a retained placenta can lead to serious complications. The most significant concern is hemorrhage, or excessive blood loss. An infection of the uterus, known as endometritis, is another potential complication. Long-term complications, though less common, can include Asherman’s syndrome, a condition involving scar tissue formation in the uterus, and, in rare instances, secondary infertility.
Treatment and Recovery
The management of a retained placenta aims to remove any remaining placental tissue from the uterus to prevent further complications. One common intervention is manual removal, often performed under anesthesia.
Medications are also used to manage retained placenta. Oxytocin is administered to stimulate uterine contractions, which helps expel the placenta and reduce bleeding. Antibiotics may be prescribed to prevent or treat infections. In severe instances, particularly with conditions like placenta accreta spectrum, surgical procedures such as dilation and curettage (D&C) or hysterectomy may be necessary to control bleeding or remove deeply embedded tissue.
Recovery after treatment involves monitoring for signs of infection or continued bleeding. Healthcare providers will advise on normal postpartum bleeding and when to seek further medical attention. Rest, nutritious food, and adequate hydration are important during recovery.