A germinal matrix hemorrhage is bleeding into the brain of premature infants caused by the rupture of fragile blood vessels within the germinal matrix of premature babies. The germinal matrix is a highly vascularized area within an unborn infant's brain from which brain cells, including neurons and glial cells, originate. Infants are at most risk to germinal matrix hemorrhages when they are born prematurely, before 32 weeks. The stresses exposed after birth, along with the fragile blood vessels, increase risk of hemorrhage. Signs and symptoms include flaccid weakness, seizures, abnormal posturing, or irregular respiration.