UCLA

Congenital syphilis is preventable, yet rising public health crisis in the United States, particularly in Los Angeles County (LAC). This intersecting epidemics of sexually transmitted infections (STI), substance use, and structural inequities disproportionately affect pregnant and birthing persons. This dissertation examines the barriers to prenatal care in the context of methamphetamine use and its contribution to the increasing rates of congenital syphilis between 2011 and 2020. Guided by a Reproductive Justice framework and Syndemic theory, this study utilized STI surveillance data and administrative data to measure burden of methamphetamine and examines how it is associated with congenital syphilis prevention barriers that are at individual, institutional, and community levels. Analytic methods included multivariate logistic regression, structural equation modeling, and spatiotemporal Bayesian modeling using integrated Nested Laplace Approximation. These methods evaluated the association between methamphetamine use and lack of syphilis treatment/prenatal care in the context of pregnancy, Syndemic risk, and policy change. Chapter Two assessed whether pregnancy status moderated the association between methamphetamine use and syphilis treatment (Aim 1). Chapter Three applied structural equation modeling to identify how Syndemic factors mediated the relationship between methamphetamine use and lack of prenatal care, with attention to racial disparities (Aim 2). Chapter Four mapped spatiotemporal trends in CS rates across LAC Health Districts, accounting for methamphetamine-related arrests and social vulnerability (Aim 3). Findings indicated that persons of reproductive potential (PRP) who are pregnant had 50% less likelihood of getting syphilis treatment compared to non-pregnant counterparts (Aim 1). Latinx birthing persons experienced high Syndemic burdens, and methamphetamine use was pronounced among Black birthing persons (Aim 2). Upward trends in methamphetamine use and prenatal care gaps emerged following policy change in 2015 (Aim 3). This dissertation aims to identify how individual and structural level determinants of health interact to shape reproductive health outcomes among pregnant persons with diagnosed (and undiagnosed) syphilis. It underscores the urgent need to integrate STI care and harm reduction approaches in conjunction with sexual and reproductive health services in areas most affected by congenital syphilis.