Congenital Syphilis Is Rising in the U.S.: What to Know if Pregnant

Cases of congenital syphilis have surged, especially in states like Florida. Early testing, treatment, and prevention can protect both parent and baby.

Rates of most sexually transmitted diseases are inching down in the U.S., but that encouraging news is not spread evenly among all groups. The U.S. Centers for Disease Control and Prevention recently reported that syphilis in infants rose yet again for the 12th consecutive year, a worrisome trend that has serious, and sometimes fatal, consequences for babies.

“We have seen these rates skyrocketing, and it’s very troubling,” says Laura Beauchamps, M.D., an infectious disease expert at the University of Miami Health System who specializes in sexually transmitted infection (STI) treatment in vulnerable populations.  “What is happening with infants is a reflection of what is happening in the general population with secondary syphilis as well.”  (In secondary syphilis, the infection has spread through the bloodstream and caused body‑wide symptoms.)

Syphilis is a preventable and curable STI.

It is caused by Treponema pallidum, a type of bacteria that spreads through sexual contact. It usually starts as a sore on the genitals, rectum, or mouth and, if left untreated, can advance through different stages (primary, secondary, latent, and tertiary). Each stage has different symptoms.

A baby is born with syphilis when the infection is present in the pregnant parent. It’s usually passed from the infected mother to the fetus through the placenta or during delivery, though the latter type of transmission is not as common. The child can be infected at any stage of the pregnancy, even if the mother displays no symptoms or the initial syphilis sore has healed.

According to data from the CDC, there were almost 4,000 cases of congenital syphilis in 2024, which is a whopping 700% higher than in 2015, when there were 495 cases. There is, however, a sliver of good news. The one-year increase between 2023 and 2024 was 2%, a slowdown from previous years, which saw double-digit increases.

Progress is uneven, however, and prevalence varies significantly across populations and regions.

Florida, for example, has among the highest congenital syphilis rates, about 105 congenital syphilis cases per 100,000 live births in 2023. (South Dakota topped the list with 482 cases per 100,000, while Vermont and Idaho had 0 cases.) Congenital syphilis cases in Florida increased 88% from 2017 to 2021.

As for the demographics, African American infants accounted for about 30% of the congenital syphilis cases in 2023 but only 14% of live births. The percentage of Hispanic/Latino congenital syphilis cases was very similar. In fact, babies from both groups make up about 60% of all congenital syphilis cases in the U.S.

The rates themselves differed, however. Black infants had a much higher prevalence (about 170 per 100,000) and Hispanic infants had a lower but still elevated rate (125 per 100,000). The highest rate — 681 cases per 100,000 live births — was among American Indian/Alaska Native infants. The lowest was among Asian newborns, 9 per 100,000.

For Hispanics, cases jumped from 66.2 per 100,000 live births in 2019 to 125.0 per 100,000 in 2023 — an 89% increase in just five years. Black babies registered a similar, albeit smaller, increase, about 74% in that time period.

Dr. Beauchamps is not surprised by those numbers, as they mirror population-wide trends.

Syphilis rates are 6.5 times higher among African American adults and nearly twice as high among Hispanic/Latino adults compared to whites, according to the CDC. Rates are also rising among women of reproductive age — hence the crisis with infected infants.

“The reasons for the disproportionately high rate of syphilis among these populations are typically the same for all [high-risk] populations,” Dr. Beauchamps says.  “The problems we see accessing the [healthcare] system in the African American community, we also see among Hispanics here in South Florida,”

These groups, she adds, face barriers to accessing early prenatal care, suffer from higher housing instability, and tend to be distrustful of the health system. In addition, access to insurance, transportation and continuity of care even after an initial medical visit is low.

These obstacles are exacerbated by other issues as well. In 2023, a shortage of benzathine penicillin G, the first‑line treatment for syphilis in pregnancy, emerged for various reasons. It was prolonged by a recall, manufacturing constraints, and higher demands because of the surge in cases.

What’s more, a pregnant woman might not take the full dose of antibiotics as instructed. Or she may get reinfected when she has sex with an untreated or newly infected partner.

“It can be very frustrating,” admits Dr. Beauchamps. “How can we still see a rising number of cases when we have all these resources available both at UHealth and Jackson?”

The CDC recommends that all pregnant women get a syphilis blood test at their first prenatal visit. Another blood test should be administered during the third trimester (28-32 weeks) as well. The agency also suggests partner testing and treatment.

Florida requirements are among the strictest in the country.

Syphilis testing mandates at three key points, including at delivery if prenatal testing in the first and third trimester is missing or outdated.

But if a woman receives no prenatal care, the chance to diagnose and treat the condition during pregnancy is lost. When an infected mother is treated during pregnancy, the baby is likely to be born healthy with minimal risk of complications. However, without testing or corresponding treatment, “the consequences are very serious and devastating,” Dr. Beauchamps says.

Left untreated, syphilis can lead to miscarriage, stillbirth, prematurity, and low birthweight. An infected infant can suffer from:

• severe anemia
• enlarged liver and spleen
• meningitis
• skin rashes
• deformed bones
• blindness or deafness
• brain and nerve problems

She urges safe-sex prevention strategies that can reduce, though not totally eliminate, transmission risk. These include condoms and routine testing, particularly for those with multiple partners. Raising awareness of the disease and how easily it can spread is also key.

“People don’t realize you can get it from oral sex,” she explains. “Any direct contact with a sore or a lesion [in the mucous membranes] can lead to transmission.”

Both the CDC and Planned Parenthood suggest using a dental dam — a thin, stretchy sheet of latex or polyurethane that acts as a barrier during oral sex — to reduce the risk of giving or getting syphilis as well as other sexually transmitted infections.              

“The good news is that syphilis is highly treatable,” Dr. Beauchamps adds, “and it’s not resistant [to antibiotics] like other STIs.”

Written by Ana Veciana-Suarez. Medically reviewed by Laura Beauchamps, M.D.,

Tags: Dr. Laura Beauchamps