Intracranial Hemorrhage – Incidence
An intracranial hemorrhage is more common in an infant born preterm. For a time, the proportion of babies born prematurely increased in the U.S. and, by 2008, it had come down to 12.1 percent. A Journal of Neurosurgery: Pediatrics study that found as much as 20 percent of infants, with a birth weight of fewer than 1,500 grams, will develop an intraventricular hemorrhage (IVH). This is one of the most common brain lesions in a premature infant. In general, the risk of intracranial bleeding in infants is lower for those brought into the world via cesarean delivery.Get A 100% Free CASE Evaluation
Over 9,500 preterm infants, born at or before 28 weeks, were documented between 2003 and 2007. Those born at 28 weeks had a 92 percent survival rate, and 16 percent of them had severe IVH. For those born at 22 weeks, IVH Grade I was present in 30 percent of them.
According to Cleveland Clinic, intracranial hemorrhage occurs in children and adults. In the United States, they account for about 10 percent of strokes. There are many causes, but in babies, it can be triggered by a prolonged, difficult delivery or eclampsia, a condition in which a pregnant woman develops seizures because of high blood pressure or excessive urinary protein. It is more frequent in young mothers in their first pregnancy.
Neonatal subgaleal hemorrhage, one type of intracranial bleeding, occurs in 0.6 out of 1,000 deliveries, according to Pediatrics International. The study found that number to increase with vacuum-assisted deliveries; in such cases, the incidence rose to 4.6 births out of 1,000. Researchers also made an effort to predict the outcome. Infants with a poor outlook included those with co-existing conditions such as anemia, renal impairment, and skull fractures. Those requiring a ventilator or blood transfusion were more at risk for complications as well.
There is not much information on the incidence of babies born with perinatal intracranial hemorrhage. The general definition of this condition is a buildup of blood inside the skull. Bleeding can be characterized as epidural, or between the skull and outside tissues, or subdural, in which blood pools up between the dura mater, or outermost membrane of tissues (meninges) surrounding the brain, and the arachnoid matter. A subarachnoid hemorrhage is when blood fills the space between that layer and the pia matter, the innermost layer of the meninges and that encloses cerebrospinal fluid. Also, blood can fill the ventricles, or spaces, of the brain, and bleeding inside the brain is referred to as an intraparenchymal hemorrhage.
Most of the time, this kind of hemorrhage occurs within the newborn’s first three days of life. Bleeding inside the head can cause major injuries. However, it is often a sign an injury has happened already. The incidence of IVH in older infants is often caused by a traumatic event, but that is not so in premature infants. An immature cerebral circulatory system and delicate cellular structures increase the risk of a pre-term infant having this problem. Sometimes the blood flow is restricted, causing cells to die off, and if the walls of blood vessels break down, even more, bleeding occurs.
Also, the incidence is broken down into four grades. Grade I IVH is limited to the germinal matrix, where cells migrate from while the brain is developing. Notably fragile, it contains neurons and glial cells. A lack of structural integrity increases the risk of bleeding in this area. Grade II bleeding involves the ventricles, while in Grade III these are enlarged by a significant volume of blood. A Grade IV IVH is when blood has entered the surrounding brain tissue.
The first two grades are more common. They often don’t lead to more complications and clear up on their own. The most dangerous are the higher grades, in which cerebrospinal fluid can be blocked by blood clots. As a result, fluid can accumulate within the brain, a condition known as hydrocephalus.
Medical conditions and some treatments for these can raise the risk of intracranial bleeding. These include interventions to help with other prematurity-related issues. Red blood cell transfusions are a risk factor, even if a cranial ultrasound comes back normal prior to the procedure. Therefore, if any risk factors are present, one should be especially vigilant of intracranial hemorrhage.