Analysis of several characteristics of blood from pregnant women with CMV infection according to maternal-fetal transmission. These include CMV viral load, cytokine profile in response to in-vitro stimulation with CMV peptides, meticulous analysis of anti CMV antibodies, maternal DNA polymorphism and microarray of gene expression.

Maternal Cytomegalovirus infection in pregnancy may cause significant morbidity in the fetus. Intrauterine CMV transmission occurs mainly during primary maternal infections, with a maternal-fetal transmission rate of about 40%. The mechanisms dictating CMV intrauterine transmission are unknown, and transmission is currently thought to be dependent on multiple factors, including the maternal and fetal immune system.

To investigate the mechanism of transmission approaching laboratory prediction of transmission, the investigators collect blood from pregnant women with primary CMV infection, and analyze several characteristics. These include CMV viral load, cytokine profile in response to in-vitro stimulation with CMV peptides, meticulous analysis of anti CMV antibodies, maternal DNA polymorphism and microarray of gene expression.

These results will be analysed according to transmission as indicated by a positive culture / Polymerase chain transcription of amniotic fluid or newborns urine / saliva.

Inclusion Criteria:

• pregnant women
• CMV infection: primary infection: (1) CMV-specific IgG seroconversion or (2) demonstration of low avidity CMV-specific IgG antibodies, (3) the primary appearance of CMV-specific IgM with no previous IgG, and (4) CMV DNA or viral products in blood Secondary infection: appearance of CMV-specific IgM with positive IgG

Exclusion Criteria:

• CMV status unclear
• spontaneous or induced abortion
• unknown fetal outcome

Pregnant women with CMV infection who are referred to the 'CMV in Pregnancy clinic' in Shaare Zedek Medical Center.