Born in a Sac: A Primer on En Caul Birth

By David Warmflash, M.D.

What do Sigmund Freud, Napoleon Bonaparte, Charlemagne, Liberace, and, in some legends, Moses, all have in common? All were –or were rumored to have been—born en caul. That means with a skin-tight, stretchy cover over the head and face. Rooted in the term ‘Caput galeatum’, Latin for ‘head helmet’, the word caul is pronounced a little differently from cowl, the head covering that comic hero Batman wore to keep his identity secret. But it’s the same idea. On rare occasions –roughly 1 in 80,000 births– a caul covers at least the head of newborn, and sometimes the entire body. But unlike the molded bat-face with pointed ears, the caul of a newborn is elastic and mostly transparent, almost like a stretched out stocking.

Throughout history, newborn cauls –sometimes called veils– have mystified people of multiple cultures. This has led to a plethora of superstitions, that such a child will enjoy good luck, for example, or that she’ll be endowed with super powers.

But a caul is just leftover membrane –the amnion, the membrane layer that encloses the fetus and amniotic fluid, and sometimes also the more external layer called the chorion, which encloses the amnion along with part of the placenta. Normally, in a vaginal birth, a newborn exits the womb free of this covering, because of prior rupture of “the water”, which really means that the membrane down at the cervix has ruptured, thereby releasing amniotic fluid and exposing the leading part of the fetus to the outside air. Similarly in a cesarean birth, usually the obstetrician cuts through the membranes before extracting the fetus, so there too there is no caul.

So, en caul birth simply means birth of a child whose water has not ruptured before he is expelled or extracted from the womb. That’s it. No superpowers, unless he grows up as Batman with the other kind of cowl. More often, caul birth happens in premature infants, probably because the amnion is still very unstretched, and therefore harder to break.

According to some research in recent years, there could be a benefit to leaving the membranes intact, on purpose, for premature cesarean deliveries. The rationale is that this may protect the child from trauma during the delivery. If the benefit is real, it’s convenient, since the presence of an intact membrane generally tells doctors that they should perform a cesarean rather than risk a vaginal birth, since the latter case increases the risk that a covered child will suffocate. In a cesarean section, there is more control, since one can see the fetus, the umbilical cord, and placenta all at once.

Now, if a child is born en caul, either intentionally or not, she can remain covered for a few minutes, while the delivery team makes preparations, so long as umbilical vessels connecting her to the placenta remain intact. Newborns have been documented to survive as long as 25 minutes in a caul, because the oxygen levels in the placenta are thought to remain fairly high. But usually it only takes a moment or so for the team to get ready, and then removal from the caul is fairly simple. It takes just a quick snip in a safe location, and then the caul can be pealed away, and the newborn will start breathing like any other. If you’re interested in seeing the removal of a newborn from a caul, check out this very popular (but graphic) video.