History: From Folklore to Science
Today we know that vascular birthmarks are not caused by anything the expectant mother does during pregnancy. But throughout most of recorded history, this was unfortunately not the case.
For many centuries and in many cultures, vascular birthmarks and other physical anomalies were thought to result from the mother's emotions during pregnancy, a theory known as "maternal impressions." According to this belief, any fears, desires, or strong emotions a woman experienced during pregnancy could have a profound effect on her child's appearance.
Some of history's most renowned physicians were proponents of this theory. For example, the Greek physician Galen believed that a pregnant woman need only look at an image of someone and her child might resemble that individual. This could be used to advantage by gazing at statues one admired, a practice that was sometimes encouraged to produce attractive children, but it could also have the opposite effect. According to Ambroise Pare, a surgical giant of the Renaissance, pregnant women who were exposed to or even imagined alarming sights risked giving birth to malformed infants.
It was widely believed that the expectant mother's mental state not only caused vascular birthmarks, but also influenced their shape and location. For example, should a pregnant woman crave or eat excessive amounts of strawberries, her child might have a vascular birthmark resembling a strawberry. Should she be startled by something and touch her face in fright, a vascular birthmark would appear in the same place on her infant's face.
The notion that the expectant mother's emotions affected her child's appearance flourished throughout the Middle Ages and the Renaissance and well into 18th century, when enlightened physicians began to question its veracity.
In the mid-18th century, the physician and anatomist William Hunter conducted a clinical study in which he concluded that pregnant women's emotions were unrelated to vascular birthmarks. This conclusion was supported by the work of his brother, John Hunter, who demonstrated that there was no direct communication between the circulatory systems of the mother and her unborn child, the route by which the mother's emotions were supposedly transmitted to the fetus.
Although the theory of maternal impressions continued even into the 19th century, it was questioned by most physicians. By the end of that century it was dismissed as humbug, at least within the medical community.
Today the expectant mother is no longer held responsible for a vascular birthmark. These anomalies are now being studied by modern scientific methods.
The theory that tumors are dependent on their blood supply (called "angiogenesis") was proposed by Judah Folkman, MD, former Scientific Director of Boston Children's Hospital's Vascular Anomalies Center. This concept has helped investigators understand how blood vessels arise and grow in the embryo and how to control tumors by destroying their blood supply.
Dr. Folkman's pioneering work are helping direct studies of how hemangiomas grow and regress and how vascular malformations begin and expand.