Sir, I can understand you have went through a emotional trauma, so I suggest you to ruleout all the usual causes of miscarriage like abnormality in uterus,fibroid in the uterus,PCOD etc ruleout this things by consulting a gynecologist which will help you in future. Sometimes thyroid problems, certain drugs, chromosomal abnormality can be a cause so get it checked. Coming to the CMV infection- it is generally transmitted via body fluids Eg:- saliva from a infected person presenting with flu like symptoms like running nose, sore throat, fever, painful glands etc but sometimes patient can be a carrier without any symptoms so avoiding coming in contact with them and maintaining a proper hygiene by regular handwashing is beneficial. Ig g levels indicate past infection also, so I am assuming that her IGm levels are positive with positive igg level,for that she needs anti viral treatment since it signifies active infection, so consult a physician for further management.