well I've learned something new this morning. for those of you, like me who are wondering what on earth a caul is:-
Wikipedia: caul
Obstetrics
In childbirth, the caul (or veil) is seen as a shimmery coating of the head and face. The caul is harmless and is easily removed by the doctor, midwife, or person(s) attending the childbirth. A child born in this way is known as a caulbearer.
Medical sources contradict the popular opinion that a distinction needs to be made in relation to the birth caul and the adhesion of the birth (amniotic) sac to the face or head of a child at birth. In this view, the birth caul is a complete membrane covering the face of the child and the amniotic sac, or amnion, is another completely different kind of membrane that surrounds the child in the womb. The caul cannot be wiped off the child's face but must be carefully peeled off, while the adhesion of the amniotic membrane is simply a residue that sometimes sticks to the face, and is part of the afterbirth material.
Taber's Cyclopedic Medical Dictionary, medterms.com[1], 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[2], 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 over the life of his career. He says that it is usually present only in premature babies.