Labor is not complete with the birth of the baby. The final stage of labor is when the placenta comes out of the uterus. Once the baby is born, the placenta is usually expelled from the uterus within 30 min. In some cases, it may not happen automatically and the placenta will be retained. If the placenta remains in the womb, it can cause infection, heavy loss of blood, and even death.
Signs and Causes
The following are signs of retained placenta:
- Discharge from vagina with a foul smell
- Large tissue pieces coming out of the placenta
- Heavy loss of blood
Some of the common circumstances resulting in retention of the placenta are as follows:
- Placenta adherens
- Placenta accreta
- Placenta percreta
- Trapped placenta
Placenta adherens is the most familiar type of retained placenta. It happens when the womb’s contractions are not strong enough to expel the placenta completely. As a result, the placenta is loosely attached to the uterus wall.
In general, the placenta is attached to the linings of uterus walls. However, in some women, the placenta gets attached to the muscular walls of the uterus, causing difficulty in expelling the placenta. This complication is called placenta accreta.
If the placenta penetrates through the wall of the uterus and gets attached to another organ such as the urinary bladder (placenta percreta), then it will be retained within the womb.
In the case of trapped placenta, the placenta is completely detached from the uterus wall, yet it fails to expel from the body. This is because the cervix closes before the placenta is expelled, and hence the placenta gets trapped inside the uterus.
In the case of premature deliveries, the risk of retained placenta increases. As the placenta needs to stay for about 40 weeks in its place, a premature labor can result in a retained placenta.
Factors such as the age of pregnant women (30 years and above), premature delivery of the baby (i.e., before the 34th week of pregnancy), still birth, and very long labor during first and second stages increase the probability of retained placenta.
Prolonged use of synthetic oxytocin during labor can also contribute to retained placentas.
If the placenta is not expelled within 60 min after delivering the fetus, it creates complications in approximately 2% of births. There is a risk of heavy bleeding—postpartum hemorrhage (PPH)—when the delivery of the placenta exceeds 30 min.
PPH is a major cause of death among women in the developing world. Most of PPH cases are linked with retained placenta. In areas where accessing care is easy, the death rates are very low.
There is an option for general anesthetic. However, more risks are encountered with breastfeeding immediately after the procedure. The body retains small amounts of drugs, which may be passed to the baby during breastfeeding. Moreover, women need to be sufficiently alert to hold and support the baby for breastfeeding.
After administering an anesthetic, physicians remove the placenta and other membranes that remain by a manual process. To prevent infection, antibiotics are given intravenously.
Treatment and Prevention
Physicians remove the placenta from the womb by any of the following methods:
- Manual removal of placenta or MROP: This method can cause infection and perforation in the uterus, and some parts of the placenta may be retained in the uterus. To avoid hemorrhage, this method of placenta removal is done within few hours of delivering the baby.
- Medicines: Drugs are given to cause the uterus to contract and expel the placenta .
In some instances, breastfeeding helps. This process makes the uterus contract sufficiently so that the placenta can be expelled from the womb. Sometimes urination is effective in expelling the placenta.
Surgery is the last option. It is used when none of the above methods work. An emergency surgery is the last resort due to complications associated with it. Recurrence of a retained placenta cannot be prevented. In fact, the probability of having a retained placenta increases in cases where women have had an earlier experience of a retained placenta. However, it does not mean that when women deliver their next child, they will face the same complications.
Reviewed by Catherine Shaffer M.Sc.