Hi, does anyone know how the CMV bloods work? I had viral bloods done after a growth scan showed the baby's head is on the 5th percentile. The results came back as I have had the infection but not recently. I asked if it would have been before this pregnancy and she said yes. How do they know that? I think she said something about going back to booking bloods but I'm not sure. She said the baby's urine would be tested when born also. Is this just a precaution. Has anyone been in a similar situation? Thanks x