Microcephaly is a neurological disorder in which the circumference of the head is smaller than the average circumference for the child's age and sex. A head circumference is defined as more than two standard deviations less than normal according to sex and age.1 2 Some academics define it as three deviations in the circumference of the head.3 Microcephaly may be congenital or may occur in the first years of life. The disorder may come from a wide variety of conditions that cause altered brain growth or syndromes related to chromosomal disorders. It is suspected that Zika fever causes microcephaly