CMV seroconversion in pregnants and the incidence of congenital CMV infection

In this study, it was aimed to determine the ratio of CMV seroconversion in pregnant women, the prevalence of maternal CMV infection and also the incidence of congenital CMV infection in their newborns in the Antalya region of Turkey. During a one-year period, CMV-specific IgG and IgM were determined in all (n: 1027) pregnant women admitted at 8 to 20 weeks of gestation, an according to the presence or absence of anti CMV-IgM and CMV-IgG, pregnant women were classified as seropositive, seronegative and having maternal CMV infection. Differentiation of primary and recurrent CMV infection in women with both CMV-IgM (+) and CMV-IgG (+) antibody was determined by the avidity index (AI) of anti-CMV IgG. Ultrasonographic examination was done and amniocentesis was performed at 21 to 23 weeks of gestation in pregnants with primary infection. CMV DNA was investigated in the amniotic fluid by quantitative polymerase chain reaction (qPCR). Pregnants with recurrent infection were followed only by ultrasonography for the presence of fetal abnormalities. Neonates born to mothers with CMV infection were examined for the findings of congenital CMV infection and screened for anti- CMV-IgM, CMV DNA and CMV antigenemia in the first two weeks of life. The rate of seropositivity was found as 98.5% and the rate of seronegativity as 1.5% in pregnant women. The prevalence of maternal CMV infection was found as 1.2% and among these pregnant women, the incidence of primary and recurrent maternal CMV infection was 0.3% (3 women) and 0.8% (12 women), respectively. Congenital CMV infection was detected in one of the newborns born to mothers with primary infection while no infection was detected in any of the newborns of mothers with recurrent CMV infection, so the incidence of congenital CMV infection was found as 0.1% and the rate of intrauterine infection following the primary maternal infection was 33%. In conclusion, seroprevalence rate of CMV in pregnants is high and most (66%) infections are recurrent maternal CMV infection in our region. Thus, it does not seem to be cost-effective to screen all pregnant women for CMV infection, as in the other countries with high seropositivity rate.