Birthmarks are blotches or marks that may appear on a baby's skin shortly after birth. They can vary in size, shape, and color, and are mostly harmless. There are two types of birthmarks, vascular and pigmented. Vascular birthmarks are caused by changes to blood vessels. Pigmented birthmarks occur when the parts of the skin important for coloring grow too much. Most birthmarks can be left alone, and some may even disappear as the baby grows. Parents should call a doctor if the birthmark becomes itchy, begins to bleed, or seems to hurt. Depending on the type and location of the birthmark, families may choose to remove it using lazer treatment or medication, or speak to a therapist if the child is embarassed of his or her birthmark.