OBJECTIVE: To examine vertical transmission rates of Cytomegalovirus, Toxoplasma Gondii and Rubella infections according to amniotic fluid PCR analysis.METHODS: A retrospective analysis of mid-trimester amniocenteses performed in in pregnancies with diagnosed maternal infection by Cytomegavirus (CMV), Rubella or Toxoplasma gondii during 1994-2008 was performed. Vertical transmission rates were observed according to the presence of the infectious agent's DNA in the amniotic fluid. A univariate regression model was also performed to investigate possible correlations between transmission and epidemiological parameters.RESULTS: Overall, 7033 amniocenteses were performed during study's period, of which 166 (2.4%) with the indication of maternal infection by CMV, Rubella or Toxoplasma. Mean maternal age was 27.4 ± 2.5 years and the mean gestational age at amniocentesis was 18.7 ± 2.5 weeks. Vertical transmission was observed in 21 cases (12.7%). Transmission rate was 17.3% in cases with infection from CMV, 9.5% from Toxoplasma gondii and 7.8% from Rubella (P = .05). Maternal age was the only parameter being significantly associated with increased risk for vertical transmission (P = .04).CONCLUSIONS: According to our results, overall vertical transmission rate marginally exceeds 10%. CMV infection is characterized by relatively higher transplacental transmission rate, while increased maternal age appears to be associated with a higher risk for vertical transmission.