| Severity of IVH | Birthweight < 750 gm | Birthweight 750-1500 gm |
|---|---|---|
| Grade 1 | 12% | 0% |
| Grade 2 | 24 | 2 |
| Grade 3 | 32 | 8 |
| Grade 4 IVH or PVHI | 45 | 22 |
There is no mortality associated with PVL, nor are there short term consequences. IVH, of course, is a different matter. There is a clear relationship between birthweight, increasing severity of IVH and mortality rate, as seen in the table at the right, which shows that early mortality increases with both decreasing birthweight and more serious IVH. In addition, Volpe has recently proposed a severity score for PVHI (grade 4 IVH) that seems to correlate with mortality.
Many therapies have been studied in an attempt to prevent IVH, as once the bleeding has occurred the damage has been done. The most effective treatment for decreasing both the incidence and severity of IVH is antenatal steroids. This has been shown to reduce total IVH, severe IVH (grades 3 and 4) and, in fact, cystic PVL as well. Postnatal management includes prevention of fluctuations in blood pressure with sedation, pain control and clustering of care, treatment of hypotension, coagulopathy and seizures and transfusion as necessary.
| Severity of IVH | Birthweight < 750 gm | Birthweight 750-1500 gm |
|---|---|---|
| Grade 1 | 5% | 4% |
| Grade 2 | 6 | 14 |
| Grade 3 | 77 | 75 |
| Grade 4 IVH or PVHI | 83 | 66 |
The short-term consequence of IVH is development of ventriculomegaly, possibly leading to posthemorrhagic hydrocephalus. This also is clearly related to both birthweight and severity of IVH. The table at the left shows the incidence of ventriculomegaly in the survivors after 14 days. As mentioned, after the initial diagnosis of IVH, serial ultrasounds are done every 1-2 weeks to monitor ventricular size.
Ventriculomegaly without development of hydrocephalus can be due to loss of periventricular white matter. This can be seen with either PVL or PVHI (grade 4 IVH). It involves a slow progression, over several weeks, of gradually increasing ventricular size, unaccompanied by signs of either increased ICP or rapid head growth. Eventually the ventricular size stabilizes, neither increasing nor decreasing. If further imaging studies (CT/MRI) are done, they will show other signs of cerebral atrophy, such as increased extra-axial spaces, increased sulci and fissures.