What are the effects of CMV on the baby?

Varies. Vast majority will have no symptoms with maternal infection and do fine. Of babies who do have congenital infection they may have low birth weight, rash, small head size, enlarged liver or spleen reaction, seizures, small head size, retardation, inflamed retina (eye) and vision loss or may seem fine at birth but present late with hearing loss, coordination problems or retardation.
Growth problems. Acute CMV infections in pregnancy can cause stunted growth in the baby. It can also cause liver problems, small brains, and eye problems.