A retained placenta is when all or part of the placenta stays inside the uterus after a baby is born. Normally the placenta detaches and is delivered within about 30 minutes of birth, but in roughly 1 to 3% of vaginal deliveries, it doesn’t come out on its own. That makes it one of the more common complications of the third stage of labor and a leading cause of serious postpartum bleeding.
How the Third Stage of Labor Works
After your baby is born, your uterus continues to contract. These contractions shrink the area where the placenta was attached, causing it to peel away from the uterine wall. Your care team typically helps this process along with what’s called active management: a medication to encourage contractions, gentle traction on the umbilical cord, and massage of the uterus through the abdomen. Most placentas deliver within 5 to 15 minutes.
When 30 minutes pass without delivery of the placenta, most guidelines consider it retained. Some countries allow up to 60 minutes of waiting if there’s no active bleeding. But the risk of complications rises with time. Women whose third stage lasts 15 minutes or longer have roughly five and a half times the odds of postpartum hemorrhage compared to those whose placenta delivers sooner. After 30 minutes, the likelihood of needing a blood transfusion triples.
Why the Placenta Gets Stuck
There are a few distinct reasons a placenta might not deliver normally, and they involve different underlying problems.
Placenta adherens is the most common type. The placenta has detached from the uterine wall but the uterus isn’t contracting strongly enough to push it out. It sits loosely inside, essentially waiting for the muscle to do its job.
Trapped placenta happens when the placenta has fully separated but the cervix closes before it can pass through. The placenta is free but physically blocked.
Abnormally invasive placenta is the most serious scenario. Here the placenta has grown too deeply into the uterine wall. In a normal pregnancy, a layer of tissue called the decidua acts as a boundary between the placenta and the uterine muscle. When that layer is absent or incomplete, placental tissue can attach directly to the muscle (accreta), grow into it (increta), or even push through the outer wall of the uterus (percreta). These conditions are far less common but carry significant surgical risks.
Who Is at Higher Risk
Several factors make a retained placenta more likely. Prior uterine surgery, including previous cesarean sections, can create scar tissue that disrupts the normal boundary between the placenta and uterine wall. A history of retained placenta in a previous pregnancy is one of the strongest predictors that it will happen again.
Preterm delivery substantially raises the risk. In a study of more than 45,000 deliveries, retained placenta occurred in about 3% overall, but rates were significantly higher at gestational ages below 26 weeks and below 37 weeks. The earlier the delivery, the more likely the placenta has trouble separating cleanly.
Other risk factors include older maternal age, prolonged use of labor-stimulating medications, and conditions that affect placental implantation such as prior infections of the uterine lining. In high-resource countries, the overall prevalence sits at about 2.7% of vaginal deliveries.
What Happens If the Placenta Doesn’t Come Out
The primary danger of a retained placenta is heavy bleeding. The uterus can’t fully contract and close off the blood vessels at the placental site while tissue remains attached. This can lead to postpartum hemorrhage, which is defined as losing more than 500 milliliters of blood after a vaginal delivery. Prolonged retention also raises the risk of uterine infection, since the tissue left behind provides an environment for bacteria to grow.
Heavy bleeding can come on quickly or build gradually depending on whether the placenta has partially separated (exposing open blood vessels) or remains fully attached. Either way, the medical team will be monitoring closely once the 30-minute mark approaches.
How a Retained Placenta Is Treated
The first steps are conservative. Your care team will encourage breastfeeding or nipple stimulation if possible, since this triggers your body to release hormones that strengthen uterine contractions. They may give additional contraction-stimulating medication or try controlled cord traction again. Some evidence suggests that certain prostaglandin-based medications can reduce the need for manual intervention.
If those efforts don’t work, the next step is manual removal. This is done under anesthesia, either regional (an epidural or spinal block) or general. The provider reaches into the uterus and carefully separates the placenta from the wall by hand. It sounds dramatic, but it’s a well-established procedure and often the fastest way to resolve the situation and stop bleeding.
When small fragments of placenta are left behind rather than the whole organ, which sometimes isn’t discovered until days or weeks postpartum, an ultrasound can help confirm the diagnosis. An echogenic mass larger than about 7 millimeters on ultrasound is highly suspicious for retained tissue, with about a 75% chance of confirming actual retained fragments on further examination. In these cases, a procedure to gently scrape or suction the remaining tissue from the uterus may be needed.
For the rare cases involving abnormally invasive placenta, treatment is more complex and may require surgical specialists. The depth of invasion determines the approach, and in the most severe cases, removal of the uterus is sometimes necessary to control life-threatening bleeding.
Recovery After a Retained Placenta
Once the placenta is fully removed, most women recover well. If manual removal was required, you can expect to receive antibiotics to prevent infection and continued monitoring of your bleeding for the first several hours. You may feel more cramping than usual as your uterus works to contract back down to its pre-pregnancy size, especially if additional contraction medications were given.
In the days and weeks that follow, the warning signs to watch for are the same as those for any serious postpartum complication: soaking through more than one pad per hour, passing large blood clots, fever or chills, foul-smelling discharge, or feeling dizzy and lightheaded. These could signal ongoing bleeding or a developing infection in the uterine lining.
If you’ve had a retained placenta once, it’s worth mentioning in future pregnancies. Your care team can plan for active management of the third stage and have additional support ready, which can make a meaningful difference in how quickly the situation is recognized and handled.