Infected in CMV prior to pregnancy. I realized there was no risk to the fetus. I want to perform amniocentesis. Is amniotic fluid used to do 16 20 wee?

Possible... My advice would be to pose this question to your ob/gyn. As you will not be the one performing the actual procedure; best to ask the professionals. There is always a small risk of miscarriage after an amniocentesis; albeit minute...So best to discuss this with your obstetrician.