Background Cytomegalovirus (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.

Purpose To 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 Methods CMV 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.

Results Of 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.

Conclusions Maternal 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.

The authors have declared no competing interest.

This project was funded by a Norman Beischer Medical Research Foundation Clinical Investigator grant to LH.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study was conducted as part of a project on the feasibility and acceptability of antenatal CMV screening (Mercy Health HREC approval 2023-019, protocol v4.0, 04 December 2024). Ethical approval for use of 2023 data from the birth records dataset was obtained under approved data-sharing provisions (Austin Health HREC 64722 and Mercy Health HREC 2020-031).

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Yes

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FUNDING STATEMENT: This project was funded by a Norman Beischer Medical Research Foundation Clinical Investigator grant to LH.

CONFLICT OF INTEREST STATEMENT: Authors declare no conflict of interest

ETHICS APPROVAL: Ethical approval for this study was obtained from the Human Research Ethics Committee of Mercy Health (Ref. no 2023-019).

All data produced in the present study are available upon reasonable request to the authors and HREC approval