Study finds serious shortcomings in prenatal syphilis screening in Ontario

Congenital syphilis is completely preventable – yet new research shows there are significant shortcomings in prenatal screening that are putting some babies at risk. With funding from the Canadian Institutes of Health Research (Institute for Population and Public Health), researchers from ICES and Queen’s University found that one in five pregnancies in Ontario did not receive syphilis screening in the first trimester. Additionally, delayed screening was more common among equity-eligible populations.

The study included 551,706 pregnancies from January 2018 to December 2023 and found that 507,169 were screened for syphilis, of which 435,162 were screened in the first trimester. While most pregnancies in the study were tested for syphilis, about three percent of these pregnancies were tested for syphilis late (in the third trimester or at delivery).

In Canada, the rate of congenital syphilis was 14.5 cases per 100,000 live births in 2023 – a 220 per cent increase since 2018 – indicating an evolving epidemiology of infectious syphilis among women. Because untreated congenital syphilis can lead to serious outcomes, including infant death, these trends underscore the importance of prenatal screening as a key preventive strategy.

Congenital syphilis should not occur in a high-income country with universal health care. When one in five pregnancies are not screened in time, it indicates that our current system is not reaching everyone equally.”

Dr. Sahar Saeed, Assistant Professor in the Department of Public Health Sciences at Queen’s University and senior author

These findings highlight the urgent need to rethink how screening is provided. “Relying solely on the traditional prenatal care model may not be sufficient to reach populations that face barriers to accessing care,” says Amanda Featherstone, lead author of the study. “Providing non-judgmental, comprehensive care with complementary strategies such as opportunistic screening and community-based outreach programs with the use of point-of-care testing is an important next step.” These approaches have shown promise in reaching disadvantaged populations and reducing access gaps.

The study “Uptake of prenatal syphilis screening and its determinants in Ontario, Canada: a population-based retrospective cohort study” is in the May issue of CMAJ.

This work was supported by a Canadian Institutes of Health Research Catalyst Grant (STBBI Research in Canada: Beyond HIV/AIDS and Hepatitis C) (number SR7-196517).