Bleeding in the brain, which occurs mainly in premature babies.

Bleeding within the ventricles of the brain. The ventricles are small chambers in the center of the brain.

IVH refers to bleeding in the brain and is most common in the smallest premature babies (those weighing less than 3 1/3 pounds). The bleeds usually occur in the first four days of life. Bleeding generally occurs near the fluid-filled spaces (ventricles) in the center of the brain. An ultrasound examination can show whether a baby has had a brain bleed and how severe it is. Brain bleeds usually are given a number from 1 to 4, with 4 being the most severe. Most brain bleeds are mild (grades 1 and 2) and resolve themselves with no or few lasting problems. More severe bleeds can cause difficulties for the baby during the hospitalization and possible complications in the future. Some will require careful monitoring of the baby's development throughout infancy and childhood.