During the first week after birth, some premature infants develop bleeding in the brain (intraventricular hemorrhage), for which there is no known treatment.

• Bleeding severity is most often minimal (grades I and II) and causes little or no noticeable brain damage.
• Grade III bleeding raises the risk for hydrocephalus (a buildup of excess cerebrospinal fluid within the brain), brain damage, or both.
• Grade IV is used to describe extensive bleeding that has damaged brain tissue and shows up on image tests.

The more immature the brain, the more fragile the brain's blood vessels and the more sensitive they are to changes in blood pressure. So extremely premature infants are at the greatest risk for this problem.

Regardless of an infant's gestational age at birth, the risk of bleeding in the brain drops significantly after the first 72 hours of life and is negligible after 7 days of age. Very premature infants typically have an ultrasound of the head (cranial ultrasound) in the first few days after birth to check for bleeding in the brain. Those who show signs of bleeding are periodically checked thereafter.

Prevention measures that can reduce the risk of bleeding in the brain include:¹

• Corticosteroid treatment, given to the mother before the birth. This treatment is typically given to help fetal lungs develop before a premature birth and is thought to make blood vessels less likely to bleed.
• Indomethacin, given to the infant after birth. This nonsteroidal anti-inflammatory drug (NSAID) tightens the brain's blood vessels, which helps control sudden changes in blood pressure in the brain.