Syphilis cases in expectant mothers have dramatically risen since the pandemic – here’s what’s driving the trend

Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. During pregnancy, this bacteria can pass from a mother with untreated syphilis, known as maternal syphilis, to her child in utero, causing the fetus to contract congenital syphilis. In January 2026, the U.S. Centers for Disease Control and Prevention reported that the rate of maternal syphilis rose by 28% from 2022 to 2024, from just over 280 to nearly 360 cases per 100,000 births. I’m a public health researcher and infectious disease nurse practitioner. I study disparities in sexually transmitted infections, or STIs, and I’m currently conducting a study on syphilis in pregnancy. A perfect storm of factors behind the rise Two factors in particular have to be taken into consideration to understand the steep rise in cases. One is the rise in syphilis cases in the general population – which naturally leads to an increase in maternal syphilis – and the other is the specific variables such as funding and access to care barriers that affect pregnant women when it comes to the spread of this disease. The overall trend of increasing syphilis rates is the result of what I would describe as a perfect storm of