Water on the brain or 'ventriculomegly' (enlargement of the ventricles) is more common than we may think. When I was 23 weeks, my baby also presented with enlarged ventricles. An MRI was performed to exclude any other anomolies that may be associated or causing the ventriculomegly, ie spinal bifida, obstruction in the brains drainage mechanism, ect. Much to my relief, everything looks normal. The fluid levels are still being monitored but babies are resilient and adapt to anything so even with increased fluid, the brain is not being pressured and therefore it is unlikely any brain damage will occur. If the hed size greatly increases compared to gestationl age, most likely it will indicate a more serious situation but one that can be treated by a shunt at birth. Think positive and congrats on the beautiful gift of life.