What Is Circumvallate Placenta?

A circumvallate placenta is when the placenta develops abnormally in pregnancy and can cause concerns such as fetal growth restriction. It’s possible to see this abnormality on ultrasound, but in most cases, it’s not discovered until after delivery.

The placenta is an organ that grows inside the uterus along with the fetus when you’re pregnant. The umbilical cord connects the placenta to the fetus, delivering nutrients and oxygen from the placenta to support the fetus until they’re born.

How does a circumvallate placenta differ from a normal placenta?

Unfortunately, sometimes there are variations in the placenta that can cause concern. One of these is a circumvallate placenta, a rare condition that affects only 1% to 2% of pregnancies.

There are two sides of the placenta: the maternal side and the fetal side and these are separated by a thin membrane. In a normal placenta, these two sides line up equally. When you have a circumvallate placenta, the fetal side is smaller than the maternal side. This occurs due to the edges of the placenta curling up and folding towards the fetal side. This curve in the placenta can cause less blood and nutrients to get to the fetus.

Signs and symptoms of a circumvallate placenta

If you have a circumvallate placenta, you might not even be aware you have it until after you’ve given birth and delivered the placenta. It doesn’t usually cause any symptoms, but sometimes, concerns arise that could mean you have this condition.

Bleeding from vagina

You might have a higher chance of vaginal bleeding with a circumvallate placenta. According to a small study, vaginal bleeding was more common in women with circumvallate placentas than those who didn’t have it.

Slow growth of the fetus

Having a circumvallate placenta can cause the fetus to receive fewer nutrients and blood than normal, and this can cause the fetus to grow slower than normal. This can cause the baby to have a low birth weight when they’re born.

Premature rupture of membranes (PROM)

PROM happens when the amniotic sac breaks (AKA your water breaking) before labor begins. It happens in about 8% of pregnancies. There are many causes of PROM, but if you have second-trimester vaginal bleeding with PROM, there’s a chance you could have a circumvallate placenta.

Preterm birth

A preterm birth means giving birth before 37 weeks of pregnancy. Having a circumvallate placenta can increase your chances of giving birth early according to a 2021 study.

Can ultrasound show a circumvallate placenta?

So how do you know if you have a circumvallate placenta versus a normal placenta? In most cases, you won’t have any signs or symptoms of this condition and it’s only noticed after you have delivered the placenta in childbirth.

Your healthcare provider can see this type of placenta on an ultrasound, usually after week 20 of pregnancy. But it’s not always easy to see and it may not be picked up during an ultrasound.

Can you deliver a healthy baby with a circumvallate placenta?

According to 2014 research, about 46% of study participants needed to have an emergency cesarean section, 11% had placental abruption where parts of the placenta pulled away from the uterine wall, and 55% needed to have their babies admitted to the neonatal intensive care unit (NICU) for monitoring.

However, there is no reliable research to indicate you would need to have a cesarean section with a circumvallate placenta and many people go on to have a vaginal delivery. If you are experiencing complications such as PROM or further concerns with the placenta, you may need to have a cesarean section. While having this condition can increase your chances of complications, it is possible to carry your baby to term and give birth vaginally.

What is the treatment for a circumvallate placenta?

Your healthcare provider can’t treat a circumvallate placenta, but they can take steps to decrease the chances of complications. If you are experiencing concerns related to this condition, your healthcare provider will look at treating those complications so they don’t worsen.

You may have extra monitoring such as additional ultrasounds if there are growing concerns with the fetus. In some cases of placental abruption, you may be placed on bed rest. If the fetus is in distress or there is a danger to you or the fetus, your provider might recommend delivery or a cesarean right away.

If you go into premature labor, you might be admitted to the hospital until your baby is ready to be born.

Can a circumvallate placenta resolve by itself?

If you’re one of the few people with this condition, you might be asking yourself if a circumvallate placenta goes away. Unfortunately, this type of placenta won’t fix itself or go away on its own. However, your healthcare provider can monitor your pregnancy more closely and keep track of the baby’s growth to help prevent any complications.