Congenital syphilis, on the rise, requires response beyond screening mandates
![A vial of blood marked "VDRL- Test [syphilis, gonorrhea]"](https://hsph.harvard.edu/wp-content/uploads/2026/03/horizontal-1.jpg)
States that expanded requirements for prenatal syphilis screening saw increased case detection, but only in the short term, according to a new study led by Harvard T.H. Chan School of Public Health. The researchers say the findings highlight the need for a more comprehensive response to congenital syphilis, which can lead to adverse birth outcomes, including neonatal or infant death, and lifelong medical complications.
The study was published March 20 in JAMA Health Forum. Sarah Baum, PhD candidate in the Department of Global Health and Population, was the corresponding author. Other Harvard Chan School authors included Jessica Cohen, professor of health economics, and Nicolas Menzies, associate professor of global health.
Historically, clinicians have been required to offer syphilis screening to pregnant patients only during the first trimester. More than 20 states have expanded this mandate in recent decades, passing laws requiring that pregnant patients be offered screening at multiple points during pregnancy. Few studies have examined the efficacy of these expanded mandates—though it’s known that congenital syphilis has surged nearly 12-fold in the U.S. over the last decade.
The researchers sought to provide the first national evidence on the impact of expanded prenatal syphilis screening mandates. Using a sample of 16.3 million live births and 20,961 reported maternal syphilis cases between 2012 and 2022, they compared case detection rates between 29 states that did not expand mandates and four that did: Arizona, Georgia, Louisiana, and Michigan, all of which required clinicians to offer syphilis screening to pregnant patients during the first and third trimesters and at delivery.
The study found that mandates were associated with a 26% increase in maternal syphilis case detection in the first quarter after they were enacted, but that this boost faded within a year. The results show that “expanded screening mandates have a real but limited effect without additional supports,” said Baum. “To effectively respond to and prevent congenital syphilis, states should pair mandates with complementary efforts: investing in systems that track whether screening is actually being offered, addressing insurance and cost-sharing barriers that may discourage patients from accepting testing, and ensuring that people who test positive can access and complete treatment.”
Read the study: Prenatal Syphilis Screening Mandates and Maternal Syphilis Case Detection
