Intraventricular Hemorrhage (IVH) is a type of brain injury that occurs much more often among premature babies than among full-term newborns. The presence of this kind of intracranial bleeding places babies at more risk for future developmental problems.
As a neonatologist, I get many questions from parents of preemies regarding this condition. I will explain here risk factors, symptoms, diagnosis, and prognosis in IVH.
Intraventricular Hemorrhage – Basic Information
Intraventricular Hemorrhage or IVH is one of the intracranial abnormalities that can be found in newborn babies after birth.
IVH – What is it?
If we cross-cut babies’ brains, we will see solid areas, which are called white and grey matter, and we will see fluid-filled chambers that are called ventricles. The role of the ventricles and cerebrospinal fluid is to provide nutrition and protection for the brain tissue.
Intraventricular hemorrhage is a condition in which blood vessels nourishing the brain rupture and blood gathers within the ventricles and around them.
In mild IVH, blood is contained within the structure called the germinal matrix, just near the wall of the ventricle. In more advanced bleeding, blood enters the ventricle and results in its dilation.
Why IVH occurs in premature babies?
Doctors believe that premature babies are more prone to IVH due to increased fragility of blood vessels in the area of the germinal matrix and due to unstable blood pressures in critically ill premature babies.
The anatomical immaturity causes increased fragility of blood vessels.
Many premature babies after birth are diagnosed with abnormal levels of oxygen or carbon dioxide, unstable glucose levels, PDA, metabolic imbalances, and anemia. In turn, these conditions may cause rapid changes in blood pressure within the brain, putting the baby at a higher risk of developing IVH.
Risk factors associated with an increased incidence of IVH
- Lower gestational age at birth
- Low Apgar scores and need for resuscitation after birth
- Unstable blood pressures
- Low oxygen levels
- Abnormally low or high carbon dioxide levels
- Severe anemia
- Low platelets or clotting problems
- Metabolic imbalances (abnormal levels of acid or glucose in the blood)
How common is IVH in premature babies?
The incidence and severity of IVH increase with decreasing gestational age at birth. It is the smallest for babies born at more than 32 weeks and highest for babies born at 24 weeks of Gestational Age (GA) or less.
Table 1 depicts the frequency and severity of IVH by gestational age among babies born between 2003 and 2007 and who lived for more than 12 hrs after birth. These babies were born in NICHD centers. Data was modified from the article published in Pediatrics in 2010.
|GA at birth in weeks||23||24||25||26||27||28|
|IVH Grade 1 + 2||18%||21%||16%||12%||11%||8%|
|IVH Grade 3||15%||12%||8%||7%||6%||4%|
|IVH Grade 4||21%||14%||13%||7%||5%||3%|
In this population, 36% of babies born at 24 weeks had severe IVH (Grades 3 or 4), and for babies born at 28 weeks that incidence was three times lower (only 7%).
Intraventricular Hemorrhage – clinical presentation
Most intraventricular hemorrhages occur during the first day after birth, and almost all of them by the end of the first week of life.
25%-50% of babies will have no obvious clinical symptoms, and IVH will be found only on routine screening ultrasound exams.
Symptoms of IVH
Babies who develop symptoms related to IVH may initially have subtle respiratory problems, an increased number of apneic episodes, and muscle tone changes. In severe cases, we will witness seizures, flaccid muscle tone, severe apnea, stupor, and even coma.
How do we diagnose IVH?
The only method to diagnose intraventricular hemorrhage is conducting brain imaging studies. The most common and the easiest is intracranial ultrasound. It is available in all hospitals, and it can be done at the bedside without any special accommodations, even in the sickest newborn babies.
The frequency and schedules for conducting ultrasounds will vary in different institutions. Most babies at risk will have one ultrasound during the first week of life, then at one month of age and the last study before discharge home. If the baby had a positive ultrasound for IVH during the first week of life, we would continue doing ultrasounds at least weekly until it is determined that baby is not anymore at risk of developing any IVH complications.
Head CT scan and head MRI are more challenging to do on babies who are sick and treated in the NICU on breathing machines. The significant advantage of CT and MRI is that they allow us to obtain a better look into the baby’s brain anatomy, and any damage that occurred there.
Based on radiographic appearance, we classify all intraventricular hemorrhages into grades 1-4 (Source).
Grade 1 – bleeding that occurs within the germinal matrix adjacent to the ventricle
Grade 2 – bleeding that occupies up to 50% of the lateral ventricle volume
Grade 3 – bleeding that occupies more than 50% of the ventricle volume and is also causing ventricular dilation
Grade 4 – periventricular hemorrhage within the brain white matter coexistent with significant lateral ventricular bleed on the same side
Intraventricular hemorrhages Grade 1 and 2 are considered to be mild bleeds, and grades 3 and 4 are severe bleeds.
Treatment of Intraventricular Hemorrhage in newborn babies
Sadly, there is no specific treatment for intraventricular hemorrhage. Management of the baby with diagnosed IVH will always include supportive therapy and constant surveillance for any complications that may occur.
Supportive therapy should include at least the following measures:
- Correction of clotting problems and low platelet levels with appropriate transfusions
- Careful management of nutrition with emphasis on fluids, electrolytes, and glucose levels
- Ensuring adequate respiratory support avoiding low oxygen levels and abnormal carbon dioxide levels
- Management of blood flow and blood pressure avoiding hyper and hypotension
- Treatment of seizures with medications if indicated
- Continuous monitoring in the NICU on pulse-oximeters and cardiorespiratory monitors
Serial monitoring of IVH with frequent cranial ultrasounds and measurements of head circumference are essential. Some doctors will order ultrasound twice a week, and others will do them once a week. The goal is to follow the size of ventricles, spot any obstruction in the flow of the cerebrospinal fluid, and look for the development of hydrocephalus.
Hydrocephalus is a complication that may need prompt management with spinal taps or placement of VP shunt (surgery).
Sometimes, when ultrasound is not able to assess the degree of brain damage well or aggressive intervention such as placement of VP shunt is needed, doctors may order head CT or MRI.
Complications and Prognosis
Some babies, particularly those who had IVH grades 3 or 4, may progress to developing Posthemorrhagic Ventricular Dilation (PHVD), also called Posthemorrhagic Hydrocephalus. This complication is an important condition to watch for, as it may require intervention and is associated with increased mortality and neurodevelopmental impairment during childhood.
It is believed that PHVD is caused by an impaired ability to absorb cerebrospinal fluid due to inflammation after blood entered ventricles. Another type of ventricular dilation may occur as a result of obstruction of cerebrospinal fluid flow caused by blood clots sitting within the ventricles.
PHVD is more common with more severe forms of IVH, at lower gestational age, and when the baby is generally sicker. Usually, ventricular dilation begins one to three weeks after the onset of intraventricular hemorrhage.
In up to 40% of cases, ventricular dilation stops progressing and does not need any intervention beyond close follow-up. However, remaining cases will require treatment with frequent lumbar spinal taps or VP shunt placement.
Different authors cite mortality rates of 20%-30% for babies with Grade 3 IVH and 40% mortality rate for babies with IVH Grade 4.
Authors of the study that summarized data from 1812 babies who were born at less than 33 weeks of GA, reported Cerebral Palsy rates for IVH Grades 1, 2, 3, and 4 are 8%, 11%, 19%, and 50% consecutively (Source).
It is still debatable whether infants with mild IVH (Grade 1 and 2) have a higher risk of neurodevelopmental impairment when compared to survivors who did not have IVH at all.
Can we prevent IVH in premature babies?
There is no way to eliminate the occurrence of IVH completely. However, there are specific approaches believed to decrease its incidence and severity:
- Transporting mothers who are in premature labor at less than 32 weeks to level 3 centers
- Treating mothers in premature labor with steroids if indicated
- Prompt treatment of amniotic sack infections (chorioamnionitis) with antibiotics
- Treating mothers in premature labor with medications slowing down contractions and delaying birth of the baby
- Prompt and adequate resuscitation avoiding abnormal levels of oxygen and carbon dioxide
- Avoidance of fluid boluses but the appropriate treatment of low blood pressure or high blood pressure
- Avoidance of rapid changes in blood glucose or acid levels
- Limiting the number of blood transfusions during the first few days of life
- Treating clotting problems and low platelets levels if needed
- Treatment of PDA (controversial as we still argue about the best approach to PDA)
If you have a premature baby born before 32 weeks receiving treatment in the NICU right now, I encourage you to explore my book “Babies Born Early“
If you are interested to find more information about other problems for which premature babies need treatment in the NICU, read my article here.
This article is only for general information purposes. It should not be viewed as any medical advice. There is a chance that information here may be inaccurate. It would be best if you always discussed all health-related matters with your doctor before making any decisions that may affect your health or health of your family members.