When a baby is born, the brain has all of the major parts, but the nerve connections that provide the basis for all motor development and cognition develop over time. As these connections are made, the brain grows, and with it the skull, at least until the child is about 5-7 years old. By then the bones that form the skull will fuse together and brain growth becomes more limited. When there is an injury to the brain at birth or in the newborn that is significant, the brain will not grow--or at least not grow to its full capacity. By age 2, this condition, known as microcephaly (which means small head), can be diagnosed by measuring the child’s head in relation to normal or average sizes for age. When microcephaly is diagnosed by the pediatrician, the reason or cause for this condition must be investigated by a thorough review of the birth history and the medical records.