Molecular detection of cytomegalovirus in pregnant women referred for the triple marker test

The study was carried out to correlate and analyze the cytomegalovirus (CMV) infection in pregnant women who had come for triple marker screening. Fifty blood samples were collected from women in the age group of 20 to 40 years and were tested for the detection of CMV by serum analysis with PCR and serological examination by ELISA technique. PCR and serological examination can detect CMV in serum samples and distinguish primary infection and recurrent infection. Twenty six per cent (13/50) blood samples from women showed PCR positivity for CMV infection. Serological examination of a 27 year old woman showed a negative IgG and a positive IgM, indicating a recent infection with CMV.


Introduction
Maternal infections are being increasingly   (2) . Infants born to mothers who are infected early in pregnancy are more likely to be small for respective gestational age and may have microcephaly Endogenous infection is the result of reactivation of latent virus (3) .
It has been reported that the prevalence of human CMV was generally high in the developing countries and those with lower socio-economic status in developed countries (4) . Human CMV prevalence was generally high among pregnant women and women of childbearing age which can have severe consequences in the offspring (5)(6)(7)(8)(9)(10)(11) . Australia, Belgium, France, Germany and USA had a low seroprevalence of 40%-60%. A high seroprevalence of CMV (> 90%) was reported from Brazil, Qatar, Saudi Arabia, Taiwan and Turkey (12)(13)(14)(15)(16)(17)(18)(19) . A varying degree of human CMV seroprevalence among different ethnic groups were found in Israel and USA (20)(21)(22) . Adequate studies pertaining to human CMV have not been carried out in India. An avidity index above 65% during the first trimester of pregnancy could reasonably be considered a good indicator of past CMV infection (23) . An IgG avidity assay in combination with an IgM ELISA could be used for monitoring pregnant women for primary CMV infection.
The aim of this study was to determine the incidence of CMV infection in pregnant women, who were referred for triple marker test (as routine screening/or due to BOH) and to correlate CMV infection with the age of pregnant women and the gestational age.

Materials and methods
A total of 50 serum samples were randomly collected from blood samples sent for Nested PCR was performed using automated, computerized and thermal cycles. Thus it indicated that the early detection of CMV antibody, before 21 weeks, can be a helpful tool to identify women at risk of transmitting infection.

Results and discussion
In the study group, a total of 50 serum samples of women of child bearing age of 20 to 40 years, were included. The DNA  One out of 13 positive CMV PCR samples also showed triple test positivity (Tables 1 and 2). These findings correlated with a study (2) which states that the rate of CMV infection in pregnant women did not increase with the age of the patient. However, it was consistently high in women of less than 30 years of age.

Table 3. CMV infection and age of pregnant women
band indicated that the sample was negative for CMV. When a correlation of the rate of CMV infection with gestational age was done it was found that at 21 weeks of gestation, a higher percentage of women were infected i.e., 50% (4/8). (Table 5).