Modelling maternal cytomegalovirus seroprevalence in Australia using maternal country of birth: Implications for antenatal screening

BackgroundCytomegalovirus (CMV) is the most common congenital infection and a leading preventable cause of neurodevelopmental disability. Contemporary maternal CMV seroprevalence estimates are needed to inform antenatal screening policy in Australia. PurposeTo estimate CMV seroprevalence among women referred for antenatal care at a tertiary maternity hospital, identify clinical and sociodemographic associations with serostatus, and model national and hospital-level seroprevalence by maternal country of birth. Materials and MethodsCMV serology results from GP antenatal referrals to a Melbourne tertiary hospital over 13 months were analysed. Seroprevalence was stratified by maternal country of birth, grouped by Organisation for Economic Co-operation and Development (OECD) membership. National and hospital-specific seroprevalence were modelled using Australian Bureau of Statistics and research dataset country-of-birth distributions. ResultsOf 4377 referrals, 591 (12.5%) included CMV serology; 61.3% were CMV IgG positive. Median gestational age at testing was 5.4 weeks; referral occurred at a median of 9 weeks. Seroprevalence was higher among women born in non-OECD countries (86.6%) versus OECD countries (54.3%) (adjusted OR 6.44, P<0.001). Modelled national maternal seroprevalence was 63.6%. Across Melbourne public hospitals, estimates ranged from 60% to 74%, reflecting demographic variation. Among 328 women tested for CMV IgM, 17 (5.2%) had positive or equivocal results; one had low avidity IgG, consistent with recent primary infection. ConclusionsMaternal CMV seroprevalence in this cohort is higher than previously reported and strongly associated with maternal country of birth. These data inform evaluation of antenatal CMV screening feasibility and cost-effectiveness studies in Australia.