Congenital cytomegalovirus (CMV) is the most common intrauterine infection and the leading infectious cause of sensorineural hearing loss and mental retardation. This article reviews the issues that relate to the diagnosis and management of this disease, detailing the points that led to the recent published guidelines by the Society of Obstetricians and Gynaecologists of Canada. A MEDLINE/Cochrane search of CMV infection, pregnancy, and prenatal diagnosis found 195 studies between 1980 and 2010. Of these, we examined 59 relevant studies. The probability of intrauterine transmission following primary infection is 30% to 40%, but only 1% after secondary infection. About 10% to 15% of congenitally infected infants will have symptoms at birth, and 20% to 30% of them will die, whereas 5% to 15% of the asymptomatic infected neonates will develop sequelae later. Children with congenital CMV infection following first trimester infection are more likely to have central nervous system sequelae, whereas infection acquired in the third trimester has a high rate of intrauterine transmission but a favorable outcome. The prenatal diagnosis of fetal CMV infection should be based on amniocentesis performed 7 weeks after the presumed time of infection and after 21 weeks of gestation. Sonographic findings often imply poor prognosis, but their absence does not guarantee a normal outcome. The value of quantitative determination of CMV DNA in the amniotic fluid is not yet confirmed. The effectiveness of prenatal therapy for fetal CMV is not yet proven, although CMV-specific hyperimmune globulin may be beneficial. Routine serologic screening of pregnant women or newborns has never been recommended by any public health authority. Target Audience: Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this educational activity, the obstetrician/gynecologist should be better able to evaluate the principles of prenatal diagnosis of congenital CMV infection so doctors will be familiar with the tests and procedures needed, in order to reach a diagnosis of congenital CMV; to assess the natural history and outcome of congenital CMV infection enabling obstetricians to counsel prenatally pregnant women with CMV; and to analyze the prognostic markers for fetal CMV, so managing physicians will be able to predict more accurately the outcomes of fetuses infected by CMV.