Human cytomegalovirus seroprevalence in three socioeconomically different urban areas during the first trimester: a population-based cohort study

Background To re-evaluate the impact of socioeconomic status and human cyto megalovirus (HCMV) seroprevalence during pregnancy, we carried out a popula tion-based cohort study. Methods IgG and IgM antibodies to HCMV and IgG avidity were studied by enzy me-linked immunosorbent assay (ELISA) in three different socioeconomic area s (SBA) in the 9-12th week of pregnancy of 1088 consecutive mothers. Results The overall IgG seropositivity was 70.7%, ranging from 60.9 to 76.4 % in 'upper' to 'lower' SEA (P = 0.0004). The HCMV IgM seropositivity was 4 .0%, ranging from 3.8% in the 'upper' and 'intermediate' SEA to 4.6% in the 'lower' SEA. Serologically acute cases, defined by low avidity of IgG, rep resented 1.7% of the pregnancies in the 'upper' SEA compared with 1.0 and 1 .1% in the other two areas. In the 'lower' SEA there were twice as many rec urrent infections as in the others, 3.6 versus 1.7%. The low impact of age did not increase after elimination of the effects of SEA and parity. Miscar riages were associated neither with IgG nor with IgM positivity, although t he percentage of greater than or equal to 2 miscarriages was 8.8% in serone gative women compared with 11.2% and 13.6% in IgG- and IgM-positive women. Conclusions Social environment seems to be the most powerful factor, predic ting both IgG seroprevalence and recurrences during pregnancy.