Expanded prenatal syphilis screening mandates show limited long-term impact on case detection

A study published in JAMA Health Forum found that state-level mandates requiring expanded prenatal syphilis screening were associated with a significant but brief increase in maternal case detection. While the surge in congenital syphilis rates has prompted several states to enact laws requiring repeat testing in the third trimester and at delivery, researchers observed that the initial improvements in detection attenuated within one year of a mandate's enactment.

Congenital syphilis rates in the United States have increased nearly 12-fold over the last decade, rising from 8.7 to 105.8 cases per 100,000 live births between 2013 and 2023. The condition, which occurs when the infection is transmitted from mother to child during pregnancy, carries severe risks, including stillbirth, neonatal death, and lifelong medical complications. Despite being almost entirely preventable through routine screening and prompt treatment, more than one-third of birth parents of affected infants in 2022 did not receive timely testing.

Researchers utilized a staggered difference-in-differences design to evaluate birth certificate data from 33 states between 2012 and 2022. The study compared 4 states that enacted mandates for third-trimester and delivery screening—Arizona, Georgia, Louisiana, and Michigan—against 29 control states that did not implement such requirements during the study period.

The mandates in these 4 states required that all pregnant individuals be offered screening during the third trimester. Additionally, 3 of the states required delivery screening for high-risk individuals, while 1 state mandated universal screening at delivery. To determine if these legislative changes translated to actual clinical practice, the investigators also analyzed inpatient discharge records from Georgia to assess changes in screening coverage.

Short-term gains and long-term attenuation

The analysis included 16.3 million live births and 20,961 reported syphilis cases. Following the passage of expanded mandates, there was a 26% (95% CI, 3-53) increase in maternal syphilis case detection during the first quarter after enactment. However, this statistical significance did not persist. By the end of the first year, the increase in case detection had attenuated to 11% (95% CI, −17 to 48; P = 0.48), rendering the impact no longer significant.

The researchers noted that while clinicians have been legally required to offer first-trimester screening in many states since the 1970s, many cases are missed without repeat testing. Although organizations such as the American College of Obstetricians and Gynecologists (ACOG) and the U.S. Centers for Disease Control and Prevention (CDC) have updated their guidelines to recommend triple screening, the effectiveness of legal mandates appears to be shaped by factors beyond simple legislation. These include clinician adherence, patient take-up, and the targeting of screening toward high-risk versus low-risk populations.

Clinical and policy implications

The study highlighted significant inequities in congenital syphilis rates, which are 12-fold higher among American Indian or Alaska Native individuals and 4-fold higher among Black individuals compared with White individuals. Furthermore, Medicaid beneficiaries experience rates 6 times higher than those with private insurance. The rising incidence has been attributed to the diversion of public health funding and reduced access to reproductive healthcare.

The authors concluded that while expanded mandates may improve near-term detection, they are unlikely to have a sustained impact without complementary efforts. Such measures include facilitating clinician adherence and ensuring that patients have the necessary access to complete their treatment after a diagnosis is made. The findings suggest that legislation alone may not be sufficient to curb the surge of congenital syphilis without addressing the underlying barriers to consistent prenatal care and treatment completion.

Reference:

Baum SE, Agha L, Menzies NA, Cohen J. Prenatal Syphilis Screening Mandates and Maternal Syphilis Case Detection. JAMA Health Forum. 2026;7(3):e260123. doi:10.1001/jamahealthforum.2026.0123