Disparities in state-mandated third-trimester testing for syphilis

Since 1999, Illinois has had a legal statute mandating both first-visit and third-trimester syphilis testing in all pregnancies. However, the incidence of syphilis infection is increasing at the national and state level, including among individuals of reproductive age, conferring risk of congenital syphilis. Although state-mandated infectious disease screening is purported to be a strategy to improve equity and quality of care, adherence to such mandates and disparities in adherence are unknown.

We sought to evaluate compliance with state-mandated third-trimester syphilis testing at a single tertiary hospital in Illinois and to identify disparities in testing.

This is a retrospective cohort study of all pregnant individuals who delivered between January 1, 2015 and February 28, 2018 at a large-volume academic center. Patients who delivered after 28 weeks of gestation were included. Frequency of state-mandated first-visit (<28 weeks) and third-trimester (≥28 weeks) syphilis screening was evaluated over the study period. The primary outcome was completion of any third-trimester screening (ie, performed as an initial or repeat test in the third trimester) in accordance with state law. Demographic and clinical factors associated with the primary outcome and with completion of both first-visit and third-trimester screening were evaluated with multivariable logistic regression.

Of the 9048 eligible deliveries, 96.9% (N=8766) of patients had first-visit syphilis screening, whereas only 27.3% (N=2469) had third-trimester screening. Performance of third-trimester syphilis testing increased over time from an average of 5.8% of deliveries during the first 6 months of the study period to 59.8% over the last 6 months of the study period. Non-Hispanic Black or Hispanic race or ethnicity, non-English primary language, public insurance, age <25, multiparity, and greater body mass index were independently associated with increased odds of third-trimester screening.

Despite a decades-old state mandate for third-trimester syphilis screening in this high-prevalence region, third-trimester screening performance was suboptimal. Several demographic characteristics were associated with adherence to screening, suggesting inequity and bias exist in testing practices. It is important to acknowledge that legal statutes do not fully eliminate bias and health disparities.