Congenital syphilis—syphilis that is passed to a fetus while someone is pregnant—is increasing in the United States. If it goes untreated, it can lead to stillbirth, preterm birth and physical and neurological deficits. Treatment is effective almost 100% of the time when it’s given according to the stage of the disease and started 30 days or more before delivery.

Syphilis in California reflect structural determinants of health including racism, with Black women experiencing the highest rates of syphilis. Among birthing parents of infants with congenital syphilis, 57% reported delayed or no prenatal care. More than half had used methamphetamines in the last year, and around one quarter had experienced incarceration or homelessness.

New research analyzing data on pregnant people with syphilis and their infants in California found that receiving late or no prenatal care, early stage of syphilis, and living in Central California were linked to congenital syphilis. For people who used methamphetamines or experienced homelessness, those factors did not impact the likelihood of preventing congenital syphilis if they were engaged in prenatal care.

This analysis identified opportunities for populations affects by methamphetamine use of homelessness, which impacts most infants with congenital syphilis in California. Entry into prenatal care is a crucial step for syphilis screening and treatment. Yet screening and treatment can also be done wherever pregnant people seek care—an emergency room, urgent care, substance use treatment facility, jail or an STD clinic. People with risk factors for syphilis may face significant barriers to entering traditional prenatal care settings. Providers could improve access to services by recognizing that prenatal care can start wherever pregnant people seek care.

To eliminate congenital syphilis, we may need creative strategies to reach people who face discrimination and stigma in existing prenatal care systems, especially those affected by homelessness and methamphetamine use.