By now, your baby's fingernails have reached the tips of the fingers. The fingernails first appeared at 12 weeks, and since the development of the arms is consistently ahead of the legs, the toenails started to develop four weeks later. The future nail begins at the tip of each finger or toe, where a nail fold is formed. At the base of this nail fold, the cells start to harden into nail, in a process known as keratinization. The nails grow from new cells formed in the soft nail bed. It takes nine weeks for the nails to reach the fingertips and it will be another four weeks before the toenails reach the tips of the toes.
The nail is actually all the same color, but the white part of the nail appears white because it does not have the nail bed, with its rich blood supply, beneath it to give the illusion of color. Since the nails already reach the fingertips, it probably won't be long after the birth before your baby's nails need trimming-they are very fine and soft and you may find it easier to trim them by nibbling them away rather than trying to cut them. Or cut them with baby nail scissors while your baby is asleep and not wiggling around.