Rubella and cmv igg are high. how serious is this?

Not necessarily: Both of these antibodies simply indicate that you have, at some time in the past, been exposed to those viruses. If they are quite high, your exposure might have been more recent. It may not have anything at all to do with current illness.

I'd think not: Having high igg to both these germs is quite desirable.It means you have been infected or vaccinated in the past & have protection circulating in your blood. A woman becoming pregnant would never want to have either infection during pregnancy as they could produce a variety of birth injuries or defects in the baby. High levels are good.