My informant for this story is my friend’s mother.
Everyone has heard that pregnant women have very powerful and often strange cravings. For example, they may crave two totally different foods that they would ordinarily not want. Whether it is because of hormones or chemicals that occur as a result of the pregnancy, it certainly seems to be true, at least based on what I have heard. My mother’s friend used to tell a joke that “If you crave something while you’re pregnant and you don’t get it, the baby will be born with a birthmark of the item that the mother was craving and didn’t get.”
I have never heard this anywhere else, except in my friend’s family. But I must admit that every time I see someone’s birthmark now, I examine it to try to discern what kind of food it most resembles and then imagine that person’s mother craving that food during the pregnancy. For example, a friend of mine has a birth mark on her left fore arm that looks very much like a strawberry. I have told her the joke and she thought it was very amusing.