A neonate is a baby who is 4 weeks old or younger.

A neonate is also called a newborn. The neonatal period -- the first 4 weeks of a child's life -- represents a time when changes are very rapid and many critical events can occur.

During the first 30 days, most present from birth (congenital) defects are discovered. Genetic abnormalities may show up. Infections such as congenital herpes, Group B Streptococcus, toxoplasmosis, and others medical conditions become apparent in the neonatal period as they begin to have effects on the baby.