A caul (Latin: Caput galeatum, literally, "head helmet") is a thin, filmy membrane, the amniotic sac, that covers or partly covers the newborn mammal immediately after birth. It is also the membrane enclosing the paunch of mammals, particularly as in pork and mutton butchery. In butchery, the caul is used as offal. In cookery, the term is sometimes applied to the fatty membrane of pork liver which has uses such as for shielding delicate meats from direct heat.
Taber's Cyclopedic Medical Dictionary, medterms.com , and Dorland's Illustrated Medical Dictionary describe a caul as a piece of amnion that sometimes envelops a child's head at birth. To be "born in a caul" is to be born with the head covered by the amnion or within an intact unruptured amniotic sac. According to healthlink.mcw.edu , Dwight Cruikshank MD, Professor and Chairman of Obstetrics and Gynecology at the Medical College of Wisconsin states that being born with or in a caul is rare, probably occurring in fewer than 1 in 1000 births, and that he has seen fewer than 10 babies with a caul throughout his career. He says that it is usually present only in premature babies. Midwives are more likely to allow babies to be born in the caul, as they perceive birth as a natural and safe event, and know that the baby is likely to be calm and not gasp for breath until the caul is removed, especially in a biodynamic birth. Some midwives believe allowing children to be born in the caul has spiritual significance; others simply think nature should be allowed to unfold as necessary.
Over the course of European history, a popular legend developed suggesting that possession of a baby's caul would give its bearer good luck and protect that person from death by drowning. Cauls were therefore highly prized by sailors. Medieval women often sold these cauls to sailors for large sums of money; a caul was regarded as a valuable talisman.
I was born with a caul, which was advertised for sale, in the newspapers, at the low price of fifteen guineas. Whether sea-going people were short of money about that time, or were short of faith and preferred cork jackets, I don't know; all I know is, that there was but one solitary bidding, and that was from an attorney connected with the bill-broking business, who offered two pounds in cash, and the balance in sherry, but declined to be guaranteed from drowning on any higher bargain. Consequently the advertisement was withdrawn at a dead loss ... and ten years afterwards, the caul was put up in a raffle down in our part of the country, to fifty members at half-a-crown a head, the winner to spend five shillings. I was present myself, and I remember to have felt quite uncomfortable and confused, at a part of myself being disposed of in that way. The caul was won, I recollect, by an old lady with a hand-basket.... It is a fact which will be long remembered as remarkable down there, that she was never drowned, but died triumphantly in bed, at ninety-two. (Charles Dickens, David Copperfield)
In the film Oscar and Lucinda, Oscar is presented, by his estranged father, with the caul that was upon his head at birth. Oscar has a phobia of the ocean and of water in general, linked to the death of his mother when he was a child. He carries this caul with him until he dies, ironically, by drowning.
Other legends also developed. One popular legend went that a caulbearer would be able to see the future or have dreams that come to pass.
Negative associations with the birth caul are rare, but in several European countries a child being born with a caul was a sign that the child may become a vampire. As a preventative measure, the caul was removed before the child was able to eat any of it, and then it was destroyed.
The most common portent of good luck in recent centuries is that the baby born with a caul will never drown, the second most common myth is from Scotland and that believes the child will be fey, or psychic. Another British meaning is that the child will travel its entire life and never tire.
Also an important myth hails from ancient Egypt, and that story claims the newborn baby is destined for the cult of Isis, again a mystically inclined fate.
Also if twins are both born with cauls it meant that they are marked by a demon and their souls are already damned.