Circumvallate Placenta - Types, Symptoms, Diagnosis, and Treatment

What Is a Placenta?

The placenta is a vital organ that develops during pregnancy, connecting the fetus to the uterine wall. It is essential for enabling the exchange of nutrients, waste products, and oxygen between the mother and the developing baby.

The placenta forms from tissues originating from the mother and the embryo, creating a unique interface where maternal and fetal blood supplies come close without mixing. This allows for the efficient transfer of substances necessary for fetal growth and development while also serving as a protective barrier against harmful agents.

Additionally, the placenta produces hormones essential for maintaining pregnancy and supporting fetal development. Following childbirth, the placenta is expelled from the mother's body. The development of the placenta begins during the implantation of the blastocyst. 32 to 64 cells contain the outer trophoblast cells and the inner cell mass. The inner cell forms the fetus and fetal membranes, and the trophoblast cell forms the placenta.

What Are the Types of Placenta?

According to the fetal membrane types, which include the chorion, mammalian placentas are classified into choriovitelline and chorioallantoic types.

The choriovitelline placenta is a placenta formed by the yolk sac and chorion. In a choriovitelline placenta, the yolk sac fuses with the chorion. Subsequently, wrinkles develop, holding the embryo to the uterine wall and the embryo, thus forming the choriovitelline placenta.

The Chorioallantoic Membrane (CAM), also known as the chorioallantois, is a highly vascularized membrane found in the eggs of certain amniotes, like birds and reptiles. It is the avian homolog of the mammalian placenta. It is formed by fusing the two extraembryonic membranes, the chorion and the allantois. It is the outermost extraembryonic membrane that lines the non-vascular eggshell membrane.

What Is the Circumvallate Placenta?

The circumvallate placenta often causes persistent vaginal bleeding from the beginning of the first trimester due to premature rupture of the membranes. It is an extracranial placenta with a raised, annular placental margin. In this condition, the chorionic plate is smaller than the basal plate. The misalignment causes hematoma retention in the placental margin, leading to poor transfer of nutrients to the fetus.

What Are the Signs and Symptoms of the Circumvallate Placenta?

The circumvallate placenta does not always show symptoms.

Some signs exhibited by the circumvallate placenta include the following:

• Vaginal Bleeding: Circumvallate placenta leads to vaginal bleeding during the first trimester.
• Premature Rupture of Membrane: Here, the amniotic sac breaks before labor. This is seen in the second trimester.
• Inhibited Fetal Growth: Fetus growth is significantly inhibited in the cases of the circumvallate placenta.

How Does the Condition Affect Pregnancy and Birth?

It increases the risk of the following conditions:

• Preterm delivery.
• Placental abortion.
• Increased risk of neonatal death.
• Chronic lung disease.
• Emergency cesarean delivery.

What Are the Treatments Done for Circumvallate Placenta Complications?

Doctors can only help manage this condition. But the following are some ways in which they can help prevent the complications that can arise out of the circumvallate placenta:

1. Restricted Growth of Fetus: The baby's development must be monitored more often. Diet and a healthy lifestyle are essential for this condition. Any form of addiction should be cut.

2. Placental Disruption: If blood loss is increased, IV fluids that help increase blood pressure may need to be given. A placental rupture causes excessive bleeding, which can put the baby or the mother's life in danger.

3. Oligohydramnios: Women with low amniotic acid need treatment that replaces the fluid lost, and the fluid transfer procedure is called amnioinfusion. This can help in the proper development of the fetus.

How Is This Condition Diagnosed?

It is difficult to diagnose and find the exact cause. Most doctors accidentally notice it during periodic scans, or the mother will have specific symptoms that point to such a condition. If not seen early, it is known only while giving birth.

What Are the Radiographic Features of the Circumvallate Placenta?

During antenatal ultrasound examinations, a peripheral rim of chorionic tissue may be observed, presenting as an echodense ridge known as a placental shelf. On 3D ultrasound, it exhibits a visual similarity to a tire, often referred to as the "tire sign."

Is Normal Delivery Possible in Circumvallate Placenta?

Circumvallate placenta outcomes vary from person to person. In most situations, the mother may need to undergo an emergency C-section. Doctors will only intervene if necessary. The primary approach is to manage the situation and facilitate a normal vaginal birth whenever possible.

What Are the Differential Diagnoses of Circumvallate Placenta?

In ultrasound imaging, a raised placental edge may manifest as an amniotic shelf (or amniotic sheet) or as a segment of an amniotic band adjacent to the placenta.

How Is Circumvallate Placenta Prevented?

Since the cause of the circumvallate placenta is unknown, there is no natural way to prevent it. The only thing that can be done is to ensure mothers have good care.

What Is the Outlook of the Circumvallate Placenta?

While some studies suggest that a circumvallate placenta might elevate the risk of complications like low birth weight, the evidence regarding its significant impact remains inconclusive. Occasionally, this condition may lead to fetal loss. Hence, providing adequate medical attention and monitoring is crucial to mitigating potential complications. Although a doctor cannot directly address the circumvallate placenta, they can implement measures to decrease risk factors for both the mother and baby.

Conclusion:

In the circumvallate placenta, the placental membrane folds back around the edges. It can cause complications such as preterm delivery, placental abruption, and the risk of neonatal death. Even an emergency cesarean will be needed. This condition has no treatment, and a diagnosis is sometimes not made until birth. Therefore, utmost care, adequate rest, and a proper diet are essential for upholding the health of the mother and fetus. Reaching out to healthcare specialists may be beneficial.