What It Means to Have a Retained Placenta
There’s a lot to marvel at when it comes to pregnancy—the body truly does some amazing things. As just one example, it creates an entire new organ specifically to help baby thrive: the placenta.
The placenta plays a crucial role in pregnancy, but once you deliver baby the special organ has served its purpose and is no longer needed. In a vaginal birth, the body delivers the placenta soon after baby is out; during a c-section, the doctor removes the placenta. In some cases, however, placenta delivery doesn’t go quite as planned and the placenta stays in the uterus, resulting in the complication known as a retained placenta.
Here’s what you should know about this complication, including symptoms and signs of a retained placenta, risk factors, treatment options and more.
A retained placenta is when either the whole placenta or a portion of it remains inside the uterus after delivery, explains Jennifer Gilner, MD, PhD, an assistant professor of obstetrics and gynecology at Duke University School of Medicine. This complication occurs in up to 3 percent of deliveries. When only parts of the placenta remain in the uterus, it’s sometimes referred to as retained placental fragments.
“Normally the placenta will spontaneously separate from the lining of the uterus shortly after delivery of the baby, triggered by strong contraction of the uterine muscle,” Gilner says. For a vaginal delivery, this typically occurs within 30 to 60 minutes, she adds.
Delivering the placenta is actually considered its own stage of labor, adds Gabriela Dellapiana, MD, a maternal-fetal medicine specialist at Cedars-Sinai in Los Angeles. “Labor and delivery are divided into three stages,” she explains. “Stage 1: dilation of the cervix; stage 2: the pushing phase with delivery of the baby; and stage 3: delivery of the placenta. The placenta is highlighted as having its own stage because failure to remove the placenta in its entirety, or in a timely fashion, increases the risk for heavy vaginal bleeding in the postpartum period.”
There are three types of retained placenta, according to the American Pregnancy Association (APA):
- Placenta adherens, the most common type of retained placenta, occurs when uterine contractions aren’t strong enough to expel the placenta, so it stays attached to the uterus.
- Trapped placenta is when the placenta does detach from the uterine wall, but stays in the uterus, usually because the cervix closes before it can be expelled.
- Placenta accreta is a condition in which “the developing pregnancy lands in or near a prior scar or abnormal uterine lining—usually from prior cesarean, though it can be from other gynecologic procedures. Then, as the pregnancy grows, the placenta forms an abnormal attachment to the uterus that cannot release after delivery,” says Gilner. The APA says this poses a severe risk of heavy bleeding and may require blood transfusions and/or a hysterectomy.
We know that delivering the placenta is critical to a birthing parent’s health and safety—so what causes a retained placenta in the first place?
Causes
According to Dellapiana and Gilner, possible causes of a retained placenta include:
- The placenta is abnormally stuck to the wall of the uterus (as discussed above)
- Inadequate uterine contraction after delivery
- The cervix begins to close before the placenta delivers
- Abnormal placental shape
- The umbilical cord detaches from the placenta prematurely
- Abnormal uterine cavity shape
Risk factors
Some risk factors that can result in a retained placenta are:
- Preterm delivery
- Prior retained placenta
- Congenital uterine anomalies
- Previous pregnancy termination, miscarriage or curettage (removal of tissue from uterus)
- History of more than five prior deliveries
“Certain conditions can increase the likelihood of having a retained placenta, such as umbilical cord abnormalities, a placenta with multiple separate lobes … [and] prior surgery on the uterus, like a cesarean delivery or fibroid removal,” adds Dellapiana.
The primary symptom of a retained placenta is heavy postpartum bleeding, also called postpartum hemorrhage, says Dellapiana. This usually occurs within 24 hours of delivery, but can sometimes be delayed for up to 12 weeks. That’s why it’s important to monitor yourself for excessive vaginal bleeding, which Dellapiana defines as “saturating more than four maxi pads in two hours and/or passing large blood clots.” Postpartum patients with a retained placenta may also experience a fever, uterine tenderness or painful cramping.
There’s a risk of infection too. “In cases where the retained placental tissue does not immediately become evident and remains in the uterus multiple days or more, an infection can develop inside the uterus,” Gilner adds.
If the placenta, whole or partial, remains in the uterus beyond 30 to 60 minutes after delivering baby, it’s considered retained. The condition continues until all pieces of the placenta have been removed, say Dellapiana and Gilner.
How a provider will treat a retained placenta will depend on various factors, such as when the condition is caught and its severity. Here are some possible treatment options, according to Dellapiana:
- Medications that will cause the uterus to contract to allow you to push out the placenta, or for the provider to manually remove it
- Surgical techniques such as “curette excision, or cleaning procedure, to gently scrape the placenta from the wall of the uterus with or without a vacuum suction”
- If retained placenta is diagnosed later in the postpartum period, a hysteroscopy, which uses a small camera and instruments to look inside the uterus and clean it out, might be needed.
- In rare circumstances where the placenta is pathologically adhered to the wall of the uterus and cannot be physically separated, a hysterectomy may be necessary to stop potentially life-threatening bleeding.
Unfortunately, there’s no way to completely prevent a retained placenta. However, providers will look for early identifiers during pregnancy when possible and take steps during delivery to provide the best care to avoid this complication.
“The ‘gold standard’ in obstetric care for preventing retained placenta is to ‘actively manage’ the placental delivery by actively giving Pitocin after the baby is delivered … as well as massaging the uterus or applying continuous gentle traction on the umbilical cord,” says Gilner. “It’s also important for the birth attendant to inspect the placenta after it comes out to ensure that the tissue appears complete.”
While a retained placenta can be a serious complication, your provider is trained to address and treat it as quickly as possible in the event you experience it. If you’re pregnant and worried about developing a retained placenta or if you’re postpartum and are concerned with how much you’re bleeding, check in with your provider to talk it through (and hopefully put your mind at ease).
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.
Plus, more from The Bump:
Gabriela Dellapiana, MD, is a board-certified ob-gyn and maternal-fetal medicine specialist practicing at Cedars-Sinai in Los Angeles. She received her medical degree from the University of California San Francisco School of Medicine.
Jennifer Gilner, MD, PhD, is an assistant professor of obstetrics and gynecology at Duke University School of Medicine in Durham, North Carolina, and a board-certified ob-gyn with a certificate in maternal-fetal medicine. She received her medical degree and PhD from the University of North Carolina Chapel Hill.
Dove Press, Retained Placenta After Vaginal Delivery: Risk Factors and Management, October 2019
Cleveland Clinic, C-Section, August 2022
American Journal of Obstetrics & Gynecology, Postpartum Retained Placental Fragments - Who Is At Risk?, December 2006
American Pregnancy Association, Retained Placenta
Johns Hopkins Medicine, Hysteroscopy
Navigate forward to interact with the calendar and select a date. Press the question mark key to get the keyboard shortcuts for changing dates.
