Microcephaly is an uncommon condition whose causes can be genetic or environmental (related to toxicity, radiation or infection). It is defined as a condition at birth in which the newborn's head circumference is less than expected for age and sex. Microcephaly can present as an isolated condition or may be associated with other symptoms, such as convulsions, developmental delays or feeding difficulties. These symptoms have varying degrees of severity and in some cases may be life-threatening. The most reliable way to assess whether a baby has microcephaly is to measure head circumference at birth and again 24 hours after birth. It is very difficult to predict the consequences of microcephaly at the time of birth, so close follow-up is needed through check-ups to monitor and evaluate affected babies. There is no specific treatment for microcephaly. Care is centered on follow-up, promotion and maximization of the child's abilities.