Currently 22 weeks pregnant, mri showed mild-moderate ventriculomegaly (14mm on both sides). what are the chances of this increasing? decreasing?

Depends on the cause: If the dilatation is caused by prior infection, vascular compromise, or obstruction to fluid flow the degree may increase. There will probably be a search for any evidence of a neural tube defect like spina bifida or other structural abnormality. Rarely, some sort of intrauterine intervention may be considered. Time will tell.