Microcephaly is a birth defect where a baby’s head is smaller than expected when compared to babies of the same sex and age. Babies with microcephaly often have smaller brains that might not have developed properly. Certain infections during pregnancy like rubella and CMV may cause this condition. Other causes include malnutrition, interruption of blood supply to fetus's brain during pregnancy and exposure to harmful substances during development. It can be diagnosed between and after the pregnancy. Microcephaly is a lifelong condition. There is no known cure or standard treatment for microcephaly. Because microcephaly can range from mild to severe, treatment options can range as well.