Mermaid Birth: What Moms-To-Be Should Know

An en caul birth occurs when the amniotic sac remains intact during the delivery process. Because it is so rare to see a baby being born in a water bag and the experience is unusual, people from all walks of life have considered it a miraculous and mystical event. Is it a medically concerning situation, or does having the sac present during birth actually have any benefits?

En caul birth: What does it mean?

En caul birth, also known as "veiled birth" or "mermaid birth." In different myths and folktales, this type of birth is linked to supernatural power, a bright future, and good luck. It is also called the "protector from drowning in life."

Delivery en caul is an extremely rare phenomenon and occurs in less than one in 80,000 births. However, what happens when the sac is usually ruptured before birth and when that does not happen?

During the pregnancy, there is a bag-like structure around the fetus that is filled with amniotic fluid. The placenta, an organ that helps the mother and fetus exchange blood, oxygen, and nutrients, and the umbilical cord, which has blood vessels that carry blood between the two, are all inside this fluid-filled room.

Amniotic fluid is made from the mother's plasma and the baby's urine. The intact fluid-filled membrane maintains a stable and safe environment for the fetus. It acts as a cushion to protect the fetus from mechanical traumas and also from infections that could get into the womb. Additionally, this environment helps with the exchange of nutrients, liquids, and other biochemical products between the fetus and mother.

"Water breaking" is a commonly known sign of going into labor. Increasing pressure in the womb breaks the amniotic sac, which feels like a leak of water to the mother-to-be. But it is also very common to not have a water break until late in labor, and as we have already talked about, in very rare cases, it may not happen on its own even after the baby is born.

Is en caul birth common?

In some birth conditions, it is more common to see the membranes stay intact during delivery.

• Cesarean delivery
• Extremely preterm deliveries (between 24th and 28th weeks of pregnancy)
• Low birth weight
• Twin pregnancies

Delivery with an intact sac is more commonly observed in cesarean births than in vaginal deliveries. The technical differences between the two delivery types might help to explain this. While uterine contraction is the main force pushing the baby in vaginal deliveries, birth with a cesarean section might be considered somewhat a gentler way to deliver the newborn. Therefore, the chances of the amniotic sac remaining intact in cesarean deliveries are higher than in vaginal births.

Also, due to their relatively low birth weight, extremely preterm-delivered babies might be born with an intact amniotic sac. In the study analyzing the birth records of extremely premature infants, i.e., those born vaginally at 24th to 27th gestational weeks, nearly 28% out of 209 babies were born with an en caul birth.

Management of en caul births

Generally, en caul birth is harmless, and it is safe to live in the amniotic sac after birth. While inside the womb, the fetus doesn't use their lungs for breathing; all necessary gas exchange happens via the umbilical cord and connection with the mother. However, the baby's lungs get their first breath of air after the first cry. Only then does breathing through the lungs begin.

The main concern in en caul birth might be associated with this transition period. If "stuck" inside the sac, would that prevent the baby from getting oxygen? Luckily, as long as the umbilical cord is still intact, blood still flows between the mother and the baby even after birth. Interestingly, an article from 1975 reports a case when the baby spent 25 minutes in the sac after birth, and at the time of the report, a three-year-old was doing well with no consequences.

Generally, rupture of the membrane, which means making a small opening at the sac after birth, is the best way to handle an en caul birth. Although it doesn't require advanced skills, it should be performed carefully to avoid unintentional injuries with the surgical instrument. After making a small hole, water leaks out, and the membrane is removed from the baby's body. This step should be performed carefully, as too-quick removal might cause damage to the skin and result in scars.

Impacts of en caul birth: Should a mother-to-be worry?

Since this type of birth is not common, mothers might not be informed about the potential consequences or benefits of such a delivery. Generally, it is considered harmless, and careful membrane removal right after delivery covers all the gaps; it is pretty much the same as other births.

As we can see from the medical literature, there are not many studies on this subject; since it happens so rarely, it is hard to look into. A study analyzing data from extremely preterm births found that en caul birth is associated with better newborn outcomes, and they recommend preserving the amniotic sac until the baby is born. Some of the benefits they mention are:

• Better oxygenation. Arterial blood pH in the umbilical cord is higher in en caul-born babies. Low pH is a sign of limited oxygen delivery to organs and tissues.
• Higher well-being score (APGAR score) after birth. After delivery, the pediatric team assesses the baby's health and scores them in the first and fifth minutes based on their appearance, activity, and vital signs. In this study, en caul-born babies performed better in the fifth-minute evaluation.

A French study reporting 14-year results also reports some benefits of unruptured membranes in extremely premature en caul-born babies:

• Higher pH in the arterial blood. It means that the baby's organs receive a good amount of oxygen.
• No change in the mortality rate. It might be thought that "being trapped" in the sac might be dangerous for the newborn. However, the study suggests that unruptured membranes do not affect the chances of newborn death.

A group from Johns Hopkins University described another interesting benefit of giving birth en caul. When the umbilical cord falls into the birth canal before the baby, this is called cord prolapse. The umbilical vessels could get squished between the baby and the birth canal, which could be life-threatening. Therefore, the safest delivery in cord prolapse cases is a C-section. In the case of a 27-week pregnancy with the umbilical cord appearing first, an unruptured amniotic sac created a protective environment and physicians delivered the baby vaginally with the umbilical cord first.

Although unusual, en caul birth is harmless and simple to manage after the birth. It is more common and has some beneficial effects in extremely premature deliveries.