Overview:
The numbers of pregnant U.S. women contracting syphilis more than tripled between 2016 and 2022 and has gained steam since then. Most demographic groups, including Black women, have seen infection rates increase by double digits.
Centers for Disease Control and Prevention data released Tuesday shows an alarming trend: a sharp increase in the number of pregnant women diagnosed with syphilis, a sexually-transmitted infection that if left untreated puts children at risk for a range of issues, including blindness.
And while the upward trajectory has accelerated — due in part to late prenatal care, or none at all, according to experts — maternal syphilis isn’t affecting all populations equally.
According to the CDC’s National Center for Health Statistics, the national rate of maternal syphilis more than tripled between 2016 and 2022, with early estimates showing that in 2024, the numbers jumped another 28%. Black mothers have seen a 30% increase in maternal syphilis rates and the increase among white women was 23%.
The biggest increase, however, was among American Indian and Alaska Native mothers, according to the data. Their infection rate jumped by 52%.
Research indicates a combination of better testing detection and a true rise in infections across several racial and ethnic groups is fueling these growing numbers.
How We Got Here
Maternal syphilis happens when several systems intended to protect pregnant women break down, experts say. Besides an absence of quality prenatal care, women are susceptible to the infection during pregnancy if they miss follow-up visits after a diagnosis as well as social vulnerability that affects every aspect of maternal healthcare.
“Delayed access to prenatal care was also associated with maternal syphilis, as more than one-third of the women [with infections] did not have a perinatal visit in the first trimester,” Dr. Robert L. Cook told JAMA Network Open in an article published last month.
The U.S. has the worst maternal mortality rates among developed countries, with women dying from childbirth at rates that are multiple times higher than many peer nations. Black women are the most vulnerable group: in 2023, their maternal death rate was three to four times the rate of white women; the rate ticked up higher in 2024.
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While there’s no indication that syphilis infection is a factor in maternal mortality crisis, the infection increases health risks for infants. In fact, the rate of congenital syphilis — when the disease is transferred from the mother to the fetus — is a major concern. The U.S. experienced an almost sevenfold increase in diagnoses of congenital syphilis between 2015 and 2024. Congenital syphilis cases have tripled in recent years and nearly 4,000 cases were reported in 2024 alone. That’s the highest number in a single year since 1994, according to the CDC.
Shooting for the Moon, Missing the Mark
Speaking with JAMA, Cook noted that the medical and public health communities had put syphilis in its crosshairs, hoping to eradicate the infection. As part of that effort, many states required pregnant women to be screened early, testing them again during their third trimester and during labor and delivery.
But many states don’t require syphilis tests for pregnant women.
“Twenty years ago, the U.S. public health system confidently presented a plan to eliminate syphilis,” he said. But the plan, Cook said, has “not gone as intended, and pregnant women and their offspring are now bearing the brunt.”
Cook noted that other research found “syphilis rates among pregnant women in Mississippi “increased nearly 10-fold between 2018 and 2023.” Meanwhile, the overall infection rate and the rate for men have both decreased over the same time period. In the early 2020s, most states began prescribing the antibiotic doxycycline to men who had an increased risk for the disease but hadn’t been infected, which may have protected them from it. But the drug is unsafe for pregnant women and isn’t recommended for women in general.
Meanwhile, the U.S. last year had a shortage of the only injectable antibiotic approved for treating syphilis in pregnant women.
Researchers say the rate of infection among pregnant women is rising because of barriers to prenatal care, economic insecurity, limited health insurance coverage, and systemic inequities that contribute to delayed or missed treatment. There’s also some concern that recent staffing and budget cuts at the CDC will limit the ability to track the epidemic’s spread and to hire the public health workers needed to reverse this trend.
Syphilis during pregnancy is treatable with antibiotics, which can prevent transmitting it to the fetus. Infected infants can face a host of adverse outcomes including brain and nerve disorders, low birthweight, preterm birth and fetal or neonatal death.