The movement of baby’s skull through the birth canal causes the asymmetrical watermelon-like shape of the head. (The process is called molding.) As you run your hands over the top of your baby’s head, you may feel ridges caused by the skull bones overlapping during the tight squeeze of labor. Molding is more noticeable in babies with larger heads and after long labors, giving evidence that baby labored, too. Molding is less noticeable in breech babies and, depending on whether or not labor occurred, may not be present at all in cesarean births. The molded head assumes a rounded shape within a few days.