Expanded prenatal syphilis screening in Manitoba, Canada: a direct short-term cost-avoidance analysis in an outbreak context

Retrospective Cohort Study of Syphilis-Related Stillbirths in Winnipeg, Manitoba From 2017-2020

OBJECTIVE

Syphilis-related stillbirths (SRSBs) disproportionately affect marginalized women with 11% of all local stillbirths having maternal syphilis as a contributory factor in 2020. This study describes the incidence and perinatal factors associated with SRSB.

METHODS

This was a retrospective cohort study of all stillbirths occurring from 1 January 2017 to 31 December 2020, at a single tertiary-level referral hospital in Winnipeg, Manitoba. Cases that met criteria for SRSB were identified from hospital records and included in the final analysis. Maternal demographics, comorbidities, prenatal care attendance, sexually transmitted infection testing, treatment, and diagnostic investigations at time of stillbirth were collected from hospital charts using a standardized data collection form. Descriptive statistics were performed to present the results.

RESULTS

The proportion of SRSB increased over the period of study from 0%-11%. Eleven cases were identified as SRSB, with diagnosis occurring intrapartum in 7 cases and antenatally in 4 cases. Of the 4 antenatal cases, only 2 had identifiable treatment responses indicated by microbiological and pathology workup. Commonly identified risk factors for SRSB were homelessness, mental illness, substance use, sexually transmitted co-infections, and lack of prenatal care.

CONCLUSIONS

Cases of SRSB are rising in Winnipeg with 11% of all stillbirths having maternal syphilis as a contributory factor by 2020. SRSBs disproportionately affect marginalized women. The dramatic and rapid changes in the epidemiology of syphilis in Winnipeg are likely shared by other Canadian regions and warrant increased prevention strategies to improve outcomes.