What to Know About En Caul Births

When a baby is born “en caul,” it means they emerge from the womb still encased (at least partially) in the amniotic sac that helped sustain them for the last nine months. These births are exceedingly rare because the fluid-filled amniotic sac usually ruptures at some point during labor.

Here, we break down everything to know about en caul births (also known as “mermaid” or “veiled” births), including how common they are, what it means if your baby is born in the amniotic sac, and whether there are any possible complications.

How Common Are En Caul Births?

En caul births are extremely rare, says Jennifer Boyle, MD, OB-GYN and medical board expert at Flo. Research indicates that they happen in less than one out of 80,000 births. While this is just an estimate (because some en caul births aren't documented), it’s an indication of how uncommon they really are. 

During the vast majority of births, the amniotic sac ruptures before delivery (also called your water breaking). In the extremely rare cases when it doesn't, you'll get an en caul birth.

Why Do En Caul Births Occur?

There are a few factors that can increase the likelihood of having a baby in the amniotic sac. For example, "en caul births happen more often during premature births than in full-term births,” says Dr. Boyle.

Here are some potential risk factors for en caul births:

• Miscarriage. If a person has a miscarriage, defined as pregnancy loss before 20 weeks, the fetus can pass still within the amniotic sac, says Dr. Boyle. 
• Preterm birth. “A smaller baby or fetus can pass through the vaginal canal with less pressure against the amniotic sac and less chance that it fully ruptures before birth,” says Dr. Boyle. 
• C-section birth. During Cesarean deliveries, an en caul birth can be done using specific surgical techniques, says Sara Twogood, MD, OB-GYN and medical board expert at Flo. “There may be some benefit in doing this for high-risk situations, such as delivery of very pre-term babies or when the placenta is vasa previa (a rare condition where blood vessels from the baby’s umbilical cord travel across the opening of the cervix).”
• Very fast delivery. When a pregnant person’s labor and delivery move extremely quickly, the amniotic sac may not have a chance to rupture. This can lead to an en caul birth.

Possible Complications of En Caul Births

You may be wondering, is an en caul birth dangerous? Rest assured that it’s not, says Dr. Boyle. “En caul births are not considered dangerous to either the baby or the birthing parent."

Adds Dr. Twogood, “There do not seem to be negative outcomes associated with an en caul delivery. Instead, any risk factors that may have led to the en caul delivery (such as extreme prematurity or placental concerns) are risk factors for complications in and of themselves.”

In other words, if a preterm baby is born en caul, they're at risk for the same complications as preterm babies born outside of the sac. According to the Centers for Disease Control and Prevention (CDC), these include breathing problems, developmental delays, feeding issues, problems with vision and hearing, etc.

Delivering a Baby in the Amniotic Sac

You likely won’t know you’ve had an en caul birth until after delivery. It isn’t something that shows up on an ultrasound or causes any symptoms. Also, during a C-section, "parents would likely not be able to tell the difference between intentionally delivering the baby en caul or a routine Cesarean,” says Dr. Twogood.

If you've had an en caul delivery, your baby will be perfectly fine—they're able to breathe within the sac until your health care provider snips it open. Fluid will come out, the amniotic sac will be removed, and your baby will emerge into the world.

Is En Caul Delivery Better?

There are no medical reasons why you would want or need to deliver your baby in the amniotic sac. While it's certainly not dangerous for the baby, it isn’t necessarily advantageous, either.

“Sometimes people view having an en caul birth as something to strive for, since it’s often thought to be a sign that the birth proceeded naturally and without medical intervention,” says Dr. Boyle. “However, it's very normal and natural for the bag of water to break during labor. I would recommend against viewing an en caul birth as a goal. It's very rare, so not likely to happen, and doesn’t provide any benefit to the baby.”