Between November 2004 and January 2005, a prospective national survey was conducted to estimate the incidence of maternal and congenital cytomegalovirus (CMV) infections detected during pregnancy or at birth. It also aimed to describe the clinical and biological contexts that led clinicians to test for CMV infection. All laboratories in France performing CMV avidity tests or direct viral detection were contacted to provide the French Institute for Public Health Surveillance with aggregated data on CMV infection diagnoses in pregnant women, fetuses, or newborns during the study period. Individual case reporting was performed by a subset of laboratories. For these cases, demographic and clinical data were collected from clinicians. A total of 75 congenital infections were identified through the subset of laboratories. Of these, 21 were symptomatic (8 confirmed by pathological examination and 13 by clinical examination of the newborns), and ultrasound abnormalities were detected during pregnancy in 70% of these cases. The annual number of congenital infections detected during pregnancy or at birth was estimated at 277 [95% CI: 204–349]. Among these cases, an estimated 30 [95% CI: 23–37] led to pregnancy terminations with abnormal pathological findings and 46 [95% CI: 33–59] to the birth of symptomatic infants, corresponding to an incidence rate of 6 affected newborns per 105 live births [95% CI: 4–8]. During the study period, 110 maternal primary infections (MPI) were identified, most of them (73%) following routine serological screening. The annual number of detected MPIs was estimated at 545 [95% CI: 490–600]. The survey highlighted a diversity of practices in the management of MIPs and the use of amniocentesis. However, our results suggest that the majority of symptomatic congenital infections are detected in France, either during pregnancy or at birth. The survey data, along with supplementary data on the follow-up of infected newborns, are useful for further analyzing the value of systematic maternal and/or neonatal screening in France. (R.A.)