Rare Placenta Problems: A Complete Guide | Dr. Rad

Receiving a diagnosis involving your placenta can feel overwhelming. The good news is that most placenta problems, including the rarest ones, can be managed effectively when the right specialist identifies them early. This guide covers both common and rare placenta complications, including vasa previa, circumvallate placenta, placenta accreta spectrum disorders, and placental insufficiency, so you understand what each condition means and when to seek expert care.

Almost 4% of all pregnancy complications involve a placental condition. With rising C-section rates and increasing use of IVF, the incidence of several rare placenta problems, particularly placenta accreta spectrum disorders, is climbing. That makes specialist awareness more important than ever.

Dr. Steve Rad is a double-board-certified Obstetrician-Gynecologist with subspecialty training in Maternal-Fetal Medicine (MFM). As a perinatologist at the Los Angeles Fetal and Maternal Care Center, he and his team have decades of experience guiding patients through exactly these diagnoses, with compassion and clinical precision. That is the Dr. Rad difference.

What is the placenta?

The placenta is an organ that develops in the uterus during pregnancy. It delivers oxygen and nutrients to your baby and removes waste from your baby’s blood through the umbilical cord. When the placenta develops abnormally, attaches incorrectly, or separates too early, the consequences for mother and baby can be serious.

Placenta previa

Placenta previa occurs when the placenta attaches lower than normal in the uterus, partially or completely covering the cervix. It affects 1 in 200 pregnancies and usually becomes apparent in the third trimester. A low-lying placenta detected earlier in pregnancy may resolve through placental migration as the uterus grows, but complete previa rarely does.

Management depends on severity. Asymptomatic cases are often handled with expectant management, including bed rest and pelvic rest, to reduce bleeding risk. This conservative approach allows the pregnancy to continue as long as possible under close monitoring, with serial ultrasounds used to track placental position and fetal well-being. However, when bleeding becomes heavy or uncontrolled, the situation shifts quickly – emergency intervention, including urgent Cesarean delivery, may be necessary to protect both mother and baby. Any vaginal bleeding requires prompt evaluation. Because vaginal delivery is unsafe when the placenta covers the cervix, most patients deliver by Cesarean section. Severe hemorrhage may require a blood transfusion.

Placental abruption

Placental abruption is a medical emergency in which the placenta separates from the uterine wall before delivery. It occurs in about 1% of pregnancies and is a leading cause of premature delivery, newborn mortality, and fetal growth restriction (FGR). In severe cases, it can lead to stillbirth. When abruption occurs, time is everything – the placenta is your baby’s lifeline, and even a partial separation can rapidly compromise oxygen and nutrient delivery. Mothers may experience vaginal bleeding, abdominal pain, continuous contractions, and fetal heart abnormalities. It is worth noting that abnormal fetal heart rate patterns are a consequence of abruption rather than a cause – they signal that the baby is already under stress and that urgent specialist intervention is needed. Dr. Rad’s team has guided patients like Shanley through this frightening diagnosis, providing the close monitoring and rapid intervention that makes the difference in outcomes. Shanley’s experience is a powerful reminder of the Dr. Rad difference: concierge-level, 24/7 access to a renowned perinatologist who treats every patient as a VIP, not just a chart number.

What is placental insufficiency?

Occurring in approximately 1 in 300 pregnancies, placental insufficiency means the placenta cannot deliver adequate blood flow, oxygen, or nutrients to the baby. This can lead to intrauterine growth restriction (IUGR), low birth weight, and reduced amniotic fluid. Patients may notice decreased fetal movement or a uterus that measures smaller than expected. Left unmanaged, placental insufficiency raises the risk of pre-eclampsia, placental abruption, preterm labor, and stillbirth.

There is no cure, but a maternal-fetal medicine specialist can significantly improve outcomes through active management. The cornerstone of that management is serial Doppler ultrasound monitoring – a state-of-the-art technique that measures blood flow velocity through the umbilical cord and key fetal vessels, including the middle cerebral artery. Changes in these waveforms can signal increasing fetal stress days or even weeks before other warning signs appear, giving your care team a critical window to act. This includes closely tracking amniotic fluid levels and administering corticosteroid injections to accelerate fetal lung maturity if early delivery becomes necessary. These steroid injections, typically given between 24 and 34 weeks, dramatically reduce the risk of respiratory distress syndrome in a premature newborn – one of the most meaningful interventions a perinatologist can offer when delivery cannot wait.

Delivery timing is perhaps the most nuanced decision in managing placental insufficiency. Deliver too early, and the baby faces the serious risks of prematurity; wait too long, and the compromised placenta may no longer sustain a safe environment. That balance – weighing Doppler findings, biophysical profile scores, gestational age, and the mother’s overall health – is precisely the kind of high-stakes, individualized judgment that requires a specialist’s expertise. That is the Dr. Rad difference.

Placental insufficiency risk factors

• Pre-eclampsia or chronic hypertension

• Diabetes

• Smoking or illicit drug use

• Blood clotting disorders

• Prior uterine surgery or C-section, which can affect placental implantation and function

• Pregnancies conceived through IVF, which carry a modestly elevated risk of placental complications

• Carrying multiples, where placental demand is significantly higher

Almost 4% of pregnancy complications include a placental condition.

If you have been told your baby is measuring small, your fluid levels are low, or your Doppler results are abnormal, please do not navigate that news alone. A high-risk OB specialist can put a clear, personalized monitoring plan in place – and that plan can make all the difference for you and your baby.

Placenta accreta spectrum: accreta, increta, and percreta

Placenta accreta spectrum (PAS) disorders occur when the placenta attaches abnormally deeply into the uterine wall. They are among the most serious rare placenta problems, and their incidence is rising directly alongside C-section rates and IVF use, because uterine scarring creates the conditions for abnormal implantation.

• Placenta accreta – the placenta attaches too deeply to the uterine wall (most common form, roughly 1 in 500 pregnancies)

• Placenta increta – the placenta embeds into the uterine muscle wall

• Placenta percreta – the placenta grows through the uterus and potentially into nearby organs such as the bladder

PAS disorders are typically diagnosed by ultrasound, with placental lakes or loss of the normal clear zone between placenta and uterine wall as key findings. MRI may be used to assess invasion depth. The standard management for significant accreta spectrum is a planned Cesarean hysterectomy, performed by a multidisciplinary team prepared for major hemorrhage and blood transfusion. In carefully selected cases where future fertility is a priority, conservative management may be considered, but this carries substantial risk and requires close specialist oversight.

Vasa previa

Vasa previa is one of the rarest placenta problems, occurring in approximately 1 in 2,500 births. It happens when fetal blood vessels from the placenta or umbilical cord run unprotected across the entrance to the birth canal. If those vessels rupture during labor, fetal hemorrhage can be rapid and fatal.

Vasa previa is often asymptomatic in the first trimester but may present with sudden heavy second-trimester bleeding. Because there are no warning signs in many cases, proactive screening is essential – especially for patients with a history of low-lying placenta, IVF conception, or a succenturiate (accessory) lobe placenta, all of which raise the risk. The gold-standard screening tool is transvaginal ultrasound with color Doppler, which can visualize the vessels crossing the cervix. This is typically performed between 18 and 20 weeks as part of a detailed anatomy scan, and again in the third trimester to confirm the diagnosis and guide delivery planning. A blood test can also rapidly confirm fetal blood in any vaginal bleeding, enabling timely intervention.

When a high-risk OB diagnoses it, outcomes improve significantly. Once your care team confirms vasa previa, they will discuss a structured management plan tailored to your situation. Recommended management includes hospitalization from around 30 to 34 weeks – allowing close monitoring of both mother and baby in a setting where an emergency response is immediately available – and planned Cesarean delivery between 34 and 37 weeks, before labor begins and before the risk of vessel rupture becomes critical. Delivering within this window is critical: studies show that when vasa previa is diagnosed prenatally and managed with planned Cesarean delivery, survival rates approach 97%, compared to outcomes that are far grimmer when the condition is discovered only at the time of rupture. This approach keeps fetal mortality very low. This is exactly the kind of high-stakes, detail-oriented care that a perinatologist like Dr. Rad is trained to provide – combining state-of-the-art ultrasound technology with the personal touch and 24/7 availability that anxious families deserve.

Circumvallate placenta

Circumvallate placenta occurs in about 1 to 2% of pregnancies, when the placenta folds back on itself during development. This reduces blood and nutrient flow to the baby, leading to fetal growth restriction, decreased amniotic fluid, and an elevated risk of placental abruption, miscarriage, or preterm birth. Ultrasound can diagnose or confirm it, sometimes with placental pathology review after delivery.

No direct treatment exists, but a structured monitoring protocol can minimize complications. Patients need additional growth scans and ultrasounds throughout pregnancy to track fetal development and amniotic fluid levels. If growth falls below acceptable thresholds, early delivery or emergency C-section may be necessary to protect the baby.

When to See a High-Risk OB for Placenta Problems

We understand that a placenta diagnosis can feel frightening, and knowing when to escalate your care is one of the most important things you can do for yourself and your baby. You should seek evaluation from a maternal-fetal medicine specialist if you experience any of the following:

• Any vaginal bleeding during pregnancy, especially second trimester bleeding

• A diagnosis of placenta previa, low-lying placenta, or vasa previa on ultrasound

• Suspected placenta accreta spectrum, particularly with a history of C-section or uterine surgery

• Reduced fetal movement or a uterus measuring small for gestational age

• A diagnosis of placental insufficiency or intrauterine growth restriction

• Sudden severe abdominal pain, which may signal placental abruption

• Pregnancy conceived through IVF, which carries elevated PAS risk

Dr. Rad and his team at the Los Angeles Fetal and Maternal Care Center specialize in exactly these situations. We treat all patients as VIPs, ensuring you feel cared for and supported from your first consultation through delivery. We understand pregnancy can be a vulnerable and anxious time, and having the right specialist in your corner changes outcomes. The team is also available for second opinions and offers virtual consultations worldwide.

Call us at (844) 473-6100 or schedule your consultation online.