Placenta Accreta

Placenta accreta is a serious pregnancy complication where the placenta grows too deeply into the wall of the uterus. Normally, the placenta detaches easily after childbirth. With placenta accreta, it remains firmly attached, which can cause severe, life-threatening bleeding when doctors try to remove it. This condition often requires a planned early delivery and surgical removal of the uterus.

What is Placenta Accreta?

Placenta accreta is a rare but serious pregnancy complication where the placenta attaches too deeply into the uterine wall. Instead of detaching easily after a baby is born, the placenta remains firmly stuck. This can lead to severe blood loss (hemorrhage) during delivery, which is a life-threatening emergency for the birthing parent. The condition is often diagnosed before birth.

Normally, the placenta grows inside the uterus and detaches from the uterine wall shortly after the baby is born. This allows for a safe delivery of both the baby and the placenta. With placenta accreta, blood vessels and other parts of the placenta grow into or through the uterine wall. This prevents the placenta from detaching naturally after birth. There are three types of placenta accreta, depending on how deeply the placenta has grown. Placenta accreta (the most common type) means the placenta attaches firmly to the muscle of the uterus. Placenta increta means the placenta grows deeper into the uterine muscle. Placenta percreta is the most severe type, where the placenta grows completely through the uterine wall and may even attach to nearby organs, such as the bladder or bowel (MedlinePlus). This condition is considered a high-risk pregnancy complication because of the potential for massive blood loss during delivery. It requires careful planning and a specialized medical team to manage the birth safely. The goal of treatment is to prevent severe bleeding and protect the birthing parent's health.

Symptoms

Placenta accreta often does not cause any noticeable symptoms during pregnancy. Many people with this condition do not experience any signs until delivery. However, some individuals may experience vaginal bleeding during the third trimester of pregnancy. This bleeding can be light or heavy and should always be reported to a healthcare provider immediately.

Because placenta accreta often has no clear symptoms, it is frequently discovered during routine prenatal care. For example, it might be identified during a standard ultrasound examination. This early detection is crucial for planning a safe delivery. If vaginal bleeding does occur, especially in the third trimester (after 28 weeks of pregnancy), it can be a warning sign. This bleeding happens because the placenta is abnormally attached and may be trying to separate from the uterine wall too early. However, vaginal bleeding during pregnancy can also be a symptom of other conditions, so it's important to have it checked by a doctor (Mayo Clinic). It is important to remember that even without symptoms, the condition can still be present. This is why regular prenatal check-ups and screenings are so important. Early diagnosis allows healthcare providers to prepare for the safest possible delivery and manage potential complications.

Causes & risk factors

The most common cause of placenta accreta is a previous uterine surgery, especially a prior cesarean section (C-section). Scar tissue from these surgeries can make it easier for the placenta to grow too deeply into the uterine wall in a future pregnancy. Other risk factors include having placenta previa, advanced maternal age, and multiple previous pregnancies.

The risk of placenta accreta increases with each C-section a person has had. For example, someone with one prior C-section has a lower risk than someone with three or more. The scar tissue from the C-section incision can alter the uterine lining, making it more likely for the placenta to implant abnormally and grow into the muscle. Another significant risk factor is placenta previa, a condition where the placenta covers all or part of the cervix (the opening of the uterus). When placenta previa occurs in someone who has also had a previous C-section, the risk of placenta accreta increases significantly. About 1 in 20 people (5%) with placenta previa and no prior C-section may develop placenta accreta, but this jumps to about 1 in 2 people (50%) with placenta previa and four or more prior C-sections (Mayo Clinic). Other factors that can increase the risk include advanced maternal age (being 35 years or older at the time of delivery), having had multiple previous pregnancies, and any other surgery on the uterus, such as a procedure to remove uterine fibroids (myomectomy) or a dilation and curettage (D&C). In vitro fertilization (IVF) pregnancies have also been linked to a higher risk of placenta accreta (MedlinePlus).

How it's diagnosed

Placenta accreta is most often diagnosed during routine prenatal care, usually through an ultrasound examination in the second or third trimester. If an ultrasound suggests the condition, a magnetic resonance imaging (MRI) scan may be used to get more detailed images. Early and accurate diagnosis is crucial for planning a safe delivery and preventing severe complications.

During a standard prenatal ultrasound, healthcare providers can often see signs that suggest placenta accreta. These signs might include an abnormal appearance of the placenta, blood vessels that extend into the uterine wall, or a lack of a clear space between the placenta and the uterine muscle. If these signs are present, further evaluation is usually recommended. An MRI scan can provide more detailed pictures of the placenta's attachment to the uterus and surrounding organs. This can help doctors determine the exact depth of placental invasion and whether other organs, like the bladder, are involved. This information is vital for surgical planning, especially in cases of placenta percreta (Mayo Clinic). In some cases, placenta accreta may not be diagnosed until delivery. This happens when the placenta does not separate from the uterine wall after the baby is born, leading to unexpected and severe bleeding. However, with advances in prenatal imaging, most cases are now identified before labor begins, allowing medical teams to prepare for a high-risk delivery (Cochrane Library).

Treatment options

The primary treatment for placenta accreta is a planned cesarean section (C-section) followed immediately by a hysterectomy (surgical removal of the uterus). This approach is usually performed between 34 and 36 weeks of pregnancy to prevent life-threatening bleeding that can occur if the placenta tries to detach. A multidisciplinary team of specialists typically manages the delivery.

A planned C-section with hysterectomy is considered the safest approach because attempting to remove the placenta from the uterus can cause massive, uncontrolled bleeding. By removing the uterus with the placenta still attached, doctors can prevent this severe hemorrhage. This procedure means that future pregnancies will not be possible. This complex surgery requires a team of experienced specialists, including obstetricians, gynecologic surgeons, anesthesiologists, and often urologists or other surgeons if the placenta has invaded other organs. Blood products, such as transfusions, are kept readily available because significant blood loss is common even with planned management (MedlinePlus). In very rare cases, and under specific circumstances, doctors might attempt to preserve the uterus. This usually involves leaving the placenta in place after the baby is born and allowing it to dissolve over time. However, this approach carries a very high risk of complications, including severe infection, delayed bleeding, and the need for a later hysterectomy. For most people with placenta accreta, especially increta or percreta, uterine preservation is not recommended due to the high risks involved (Cochrane Library).

Recovery & outlook

Recovery from placenta accreta treatment, which often includes a C-section and hysterectomy, involves healing from major surgery. The outlook for people with placenta accreta is generally good when the condition is diagnosed before birth and managed by an experienced medical team. However, serious complications, such as heavy bleeding, infection, or damage to other organs, are possible.

After a C-section and hysterectomy, recovery typically involves a hospital stay of several days. You will need time to heal from the surgery, which includes managing pain and gradually increasing your activity level. Your medical team will monitor you closely for any signs of complications, such as infection or further bleeding. Since a hysterectomy involves removing the uterus, you will not be able to become pregnant again. This can be an emotional aspect of recovery for some individuals. Support and counseling may be helpful during this time. It's important to discuss any concerns about your physical and emotional recovery with your healthcare provider (Mayo Clinic). While placenta accreta is a serious condition, the outlook has significantly improved with early diagnosis and planned, multidisciplinary management. The main goal is to prevent the life-threatening hemorrhage that can occur during delivery. With careful planning and an expert team, most people recover well, though the experience can be physically and emotionally challenging (Cochrane Library).

When to see a doctor

You should always contact your doctor if you experience any vaginal bleeding during pregnancy, especially in the second or third trimester. While placenta accreta often has no symptoms, bleeding can be a sign of this or other serious complications. Regular prenatal care is essential, particularly if you have risk factors like a history of C-sections.

If you have a history of C-sections or other uterine surgeries, or if you have been diagnosed with placenta previa, it is especially important to discuss these risk factors with your healthcare provider. They can monitor you more closely for signs of placenta accreta during your prenatal appointments. Even if you don't have known risk factors, any unusual symptoms during pregnancy warrant a call to your doctor. This includes not only vaginal bleeding but also severe abdominal pain or any other concerning changes. Your doctor can evaluate your symptoms and determine if further testing or immediate care is needed. Early and consistent prenatal care allows your medical team to identify potential complications like placenta accreta before they become emergencies. If placenta accreta is suspected or diagnosed, your doctor will work with you to create a personalized delivery plan that ensures the safest possible outcome for both you and your baby (MedlinePlus).

Frequently asked questions

Can placenta accreta be prevented?

Placenta accreta cannot be directly prevented. However, understanding and managing risk factors, particularly the number of C-sections, can be important. If you have had a C-section, discussing future pregnancy plans and risks with your doctor can help with early detection and management.

Is placenta accreta painful during pregnancy?

Placenta accreta itself usually does not cause pain during pregnancy. The most common symptom, if any, is vaginal bleeding, which may or may not be accompanied by discomfort. Any pain or bleeding during pregnancy should be reported to your doctor immediately.

Can I have another baby after placenta accreta?

If your treatment for placenta accreta involved a hysterectomy (removal of the uterus), you will not be able to become pregnant again. This is a common outcome for severe cases of placenta accreta. In very rare cases where the uterus is preserved, future pregnancy may be possible but carries significant risks and would require extensive medical consultation.

How common is placenta accreta?

Placenta accreta is considered a rare condition, but its incidence has been increasing, largely due to the rise in C-section rates. While specific numbers vary, it is estimated to occur in about 1 in 500 to 1 in 2,000 pregnancies. The risk is significantly higher for individuals with multiple prior C-sections and placenta previa.

What are the risks to the baby with placenta accreta?

The primary risk to the baby with placenta accreta is premature birth, as delivery is often planned between 34 and 36 weeks of pregnancy to prevent life-threatening bleeding for the birthing parent. Premature babies may face health challenges related to early birth, but careful planning helps manage these risks.

What is the difference between placenta accreta and placenta previa?

Placenta previa is when the placenta covers all or part of the cervix, the opening of the uterus. Placenta accreta is when the placenta grows too deeply into the uterine wall. While distinct conditions, placenta previa is a major risk factor for placenta accreta, especially if you have also had previous C-sections.

Sources

• MedlinePlus — Placenta Accreta
• Mayo Clinic — Placenta Accreta
• Cochrane Library — Placenta Accreta