Objectives The cause of the long term neurological morbidity seen in survivors of premature birth is still largely unknown but studies have revealed that small fluctuations in oxygen tension can cause damage to the cerebral white matter. These fluctuations are part of the explanation for retinopathy of prematurity. We wished to see if fluctuating oxygen had any effect on the cerebral blood vessels.

Method We used magnetic resonance angiography (MRA) to compare the cerebral vasculature of newborn rats reared for 14 days in either room air or variable oxygen set around a mean of 10 kPA. We compared the volume of 4 major arteries in the brain: anterior cerebral artery, middle cerebral artery, internal carotid artery and basilar artery.

Results We found the rats exposed to variable oxygen had significantly decreased total volume of cerebral vasculature when compared to the room air control group, p = 0.0229. When compared individually, there was a trend towards a similar finding but the results were not statistically significant.

Conclusion It is appreciated that small fluctuations in oxygen tensions can cause harm. Where and when most damage occurs needs to be explored further. Our data shows that variable oxygen has an effect on the volume of the cerebral vasculature. By combining further animal work with human infant studies, it will be possible to build up a clearer picture of how oxygen affects vessel development in the brain, and whether this contributes to long term neurodevelopmental deficits.