The purpose of this study is to find a correlation between function of cytomegalovirus -specific T cells and the probability for intrauterine transmission.

Fetal infection with CMV is the most common cause of intrauterine infection. Only 40% of pregnant women with primary CMV transmit the virus to their fetus. Many of these women are referred to amniocentesis and many elect to terminate pregnancy without knowledge about fetal infection or damage. Currently it is assumed that transmission is dictated by variety of factors including maternal and fetal immune system. Efforts to find correlation between maternal immune system and fetal infection which can be used as a diagnostic marker were unsuccessful.

Our hypothesis is that there is a correlation between cellular immune response of the mother to CMV infection and viral transmission to the fetus.

Pregnant women with primary CMV infection (40% of whom are expected to be transmitters)and with pre-conception immunity will participate in this study.

Blood from these women will be incubated with CMV peptides and T cell activation will be measured by the secretion of various cytokines.

Inclusion Criteria:

• Pregnant women
• CMV IgG sero-conversion or the presence of low avidity IgG antibodies or the presence of IgM with no previous IgG antibodies.

Exclusion Criteria:

• Underlying immune deficiencies
• Other pregnancy complications

Pregnant women with primary CMV