Cytomegalovirus prevalence in pregnant women: the influence of parity.

Over 20,000 women attending for antenatal care at three London hospitals were prospectively studied to determine the prevalence of cytomegalovirus (CMV) antibodies; 54.4% of these women were CMV seropositive. Ethnic group was strongly associated with CMV status: 45.9% of white women were seropositive, 88.2% of Asian, and 77.2% of black women (African/Caribbean ethnic origin). Among 12,159 white women born in the British Isles, seropositivity was independently associated with increasing parity, older age, lower social class, and being single at antenatal booking. The findings are consistent with the hypothesis that, in the UK, child to mother transmission of infection plays a significant part in the acquisition of CMV infection in adult life.