How serious is a circumvallate placenta?

A circumvallate placenta can sometimes lead to complications such as restricted baby growth, bleeding, or early delivery. But these risks can often be managed with good prenatal care.

Circumvallate vs circummarginate placenta: what’s the difference?

A circumvallate placenta has edges that fold back over the surface, forming a thick, raised ring. In contrast, a circummarginate placenta also has a ring, but it’s flat with no folding.

Circumvallate Placenta: Causes, Risks, and Pregnancy Care

Learning that you have a circumvallate placenta might leave you with questions and concerns. It’s not something you hear about often, and it may sound complicated at first. A circumvallate placenta is a condition where the shape or placement of the placenta is slightly different from the usual. But do not panic, as it doesn’t always mean something will go wrong. Many people go on to have healthy pregnancies and deliveries with this condition. It's normal to feel unsure or even worried when you hear something unexpected. But understanding the basics can help you feel more prepared and less overwhelmed.

What is a Circumvallate Placenta?

The placenta is an important organ that forms during pregnancy to supply your baby with oxygen and nutrients while removing waste. A circumvallate placenta is when the placenta develops abnormally, causing its foetal side (the part closest to the baby) to be smaller than the maternal side (the part attached to the uterus).

This happens because the foetal membranes (amnion and chorion) fold back around the edges and create a raised ring or ridge. This abnormal shape can restrict the flow of blood and nutrients to your baby. It’s a rare condition, occurring in only 1 to 2 per cent of pregnancies. You may not notice it until delivery, although it can sometimes be detected during a routine ultrasound around the 20th week.

How is a Circumvallate Placenta Different from a Normal Placenta?

A normal placenta looks like a flat disc, about 10 inches long and an inch thick. The foetal and maternal sides are well aligned, allowing for smooth transfer of oxygen and nutrients. In a circumvallate placenta, the foetal side is smaller and the edges curl inward. This folding can reduce the surface area available for nutrient exchange and may impact your baby’s growth.

Circumvallate Vs Circummarginate Placenta

As already mentioned, a circumvallate placenta has a thick, raised ring around the edge due to folded membranes. In contrast, a circummarginate placenta has a similar ring of membranes, but it is flatter and less pronounced with no significant folding. This variation is generally considered less likely to cause complications.

Signs and Symptoms to Watch For

A circumvallate placenta doesn’t always cause noticeable symptoms. However, there are a few signs that might suggest its presence:

Vaginal bleeding: You might experience persistent vaginal bleeding in the first trimester.
Slow foetal growth: If your baby isn’t growing as expected during check-ups, it might be linked to this condition.
Premature rupture of membranes (PROM): This is when the amniotic sac breaks before labour starts, before 37 weeks.

How Does a Circumvallate Placenta Affect Your Pregnancy?

Not every case results in problems, but it’s important to understand the potential risks so you can work closely with your doctor to manage them:

Placental abruption: This is a serious emergency where the placenta detaches from the uterus too early. It causes heavy bleeding and may endanger you and your baby.
Low birth weight: Because the placenta may not deliver enough nutrients, your baby might be born smaller than expected.
Oligohydramnios: This means there’s less amniotic fluid than normal, which is crucial for cushioning your baby and supporting their development. Low fluid can also compress the umbilical cord and affect nutrient delivery.
Increased need for emergency C-section: You may need an emergency caesarean due to complications like foetal distress or abruption.
Neonatal intensive care: Babies born to parents with a circumvallate placenta might need extra care in the neonatal intensive care unit (NICU).
Risk of miscarriage or neonatal death: In severe cases, this condition can lead to miscarriage or neonatal death.
Chronic lung disease in babies: Infants may develop chronic lung issues due to preterm delivery or low birth weight.

Causes and Risk Factors of a Circumvallate Placenta

The exact cause of a circumvallate placenta isn't known. This condition appears to result from abnormal placental implantation early in pregnancy, but it’s not something you can cause or prevent. It can affect people of any age, background or lifestyle with no clear risk factors. A circumvallate placenta is simply a rare variation in how the placenta forms. Since it's not linked to your actions or choices, there’s no reason to feel guilty if you're diagnosed.

How is a Circumvallate Placenta Diagnosed?

Diagnosing a circumvallate placenta can be tricky because it often doesn’t show clear symptoms. Most cases are found after delivery when the placenta is examined. However, routine ultrasounds around the 20th week might reveal the abnormal shape. If your doctor suspects this condition, they may order more detailed scans to confirm it.

Managing Complications of a Circumvallate Placenta

There’s no way to fix the placenta itself, but doctors can manage the complications to improve outcomes for you and your baby:

Intrauterine growth restriction (IUGR): If your baby’s growth is slow, your doctor will monitor them closely with frequent ultrasounds. They’ll likely advise a nutritious diet, plenty of rest, and quitting smoking if you use tobacco. Early delivery may be recommended if growth is severely affected.
Placental abruption: If the placenta detaches early, you might need IV fluids to stabilise your blood pressure or a blood transfusion for heavy bleeding. Bed rest may be prescribed if it’s too early to deliver. In severe cases, an emergency C-section might be necessary to protect you and your baby.
Oligohydramnios: Low amniotic fluid requires extra monitoring. A treatment called amnioinfusion, where fluid is added to the amniotic sac, may be used to protect the umbilical cord and support lung development. Though more research is needed on its effectiveness.
Preterm birth: If you go into early labour, your doctor may recommend bed rest, IV fluids, or medications to stop labour and help your baby’s lungs mature faster with corticosteroids.

Can You Have a Vaginal Delivery?

Yes, it’s possible to have a vaginal delivery with a circumvallate placenta, and many individuals do carry to term without complications. However, the condition increases the chance of needing an emergency C-section if complications arise.

A circumvallate placenta is a rare variation in how the placenta forms during pregnancy. You may need more frequent monitoring to track your baby’s growth and amniotic fluid levels. Let your doctor know if you notice anything unusual. Keep asking questions, follow medical advice and trust that you're not alone in this.

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FAQs on Placenta Problems in Pregnancy: What Scan Reports Mean

How serious is a circumvallate placenta?
A circumvallate placenta can sometimes lead to complications such as restricted baby growth, bleeding, or early delivery. But these risks can often be managed with good prenatal care.
Circumvallate vs circummarginate placenta: what’s the difference?
A circumvallate placenta has edges that fold back over the surface, forming a thick, raised ring. In contrast, a circummarginate placenta also has a ring, but it’s flat with no folding.

Placenta Problems in Pregnancy: What Scan Reports Mean

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