US congenital syphilis cases are higher than they’ve been in almost 30 years. Here's what that means.

Congenital syphilis is on the rise in the United States, according to the Centers for Disease Control and Prevention (CDC). With more than 2,000 cases reported in 2021, the numbers are the highest since 1994.^[][]

Doctors say the rise appears to be directly linked to syphilis in the general population and among pregnant people, as congenital syphilis impacts newborns. They encourage risk reduction efforts through syphilis screening, treatment, and follow-up with pregnant patients.

Congenital syphilis risk factors

US congenital syphilis case numbers increased more than fourfold from 2015 to 2020, according to CDC data. During this period, syphilis case numbers among women ages 15 to 44 years more than tripled.^[] 

Congenital syphilis risk factors

When a pregnant person is infected with syphilis, their baby can be at risk for contracting congenital syphilis. Using condoms during sex and ensuring that both partners are tested for sexually transmitted infections (STIs) can reduce risks of contracting syphilis and passing it to a child through pregnancy.^[]

Pregnant people who are infected with syphilis can still reduce their baby’s risk of contracting congenital syphilis or—experience severe outcomes—through treatment. Syphilis can be treated with a penicillin regimen initiated 30 days or more before delivery. Quickly diagnosing and treating pregnant people can reduce risks for their baby, according to the CDC.^[]

Richard Burwick, MD, MPH, OB/GYN Residency Site Director at Pomona Valley Hospital Medical Center in Pomona, CA, says, “it is critical that doctors maintain a standardized approach to syphilis screening, treatment, and follow-up in pregnancy,” particularly in the early third trimester and in at-risk patients.

At-risk patients include people with poor access to prenatal ­care or those who reside in unstable housing environments.

“Social vulnerabilities, including homelessness, substance abuse, and incarceration, increase the barriers to timely diagnosis and treatment of syphilis,” Dr. Burwick says.

Screening is important even for people who do not express symptoms, as the disease can be asymptomatic and symptoms can be similar to those of other health problems, according to the CDC.^[] 

Congenital syphilis consequences

Congenital syphilis can make babies vulnerable to a wide spectrum of health problems, including premature death. About 40% of babies born to people with untreated syphilis can be stillborn or die from the infection shortly after birth, according to the CDC.^[]

“The majority of newborns with congenital syphilis have no symptoms or signs of disease at birth, but severe symptoms may arise over the first few years of life,” Dr. Burwick explains. He adds that “those with immediate symptoms at birth often have more severe disease.”

According to the CDC, some consequences of congenital syphilis in newborns include:^[]

• Bone damage

• Severe anemia

• Enlarged liver and spleen

• Jaundice

• Nerve problems causing blindness or deafness 

• Meningitis

• Skin rashes

Syphilis can also impact almost all organs in the body, often targeting the bones, liver, pancreas, intestines, kidney, and spleen. Because of this, Burwick encourages doctors who are determining a treatment plan for a newborn with congenital syphilis to first “determine the extent of organ system involvement.”

This can be done, he adds, through various tests, including lumbar puncture or spinal tap, blood tests, liver function tests, skeletal survey, hearing and eye exams, and, in some cases, brain imaging. 

“Regardless of the results of these evaluations, neonates with proven or high probability of congenital syphilis should receive a 10-day course of IV penicillin,” Dr. Burwick says. “Their clinical examination should be monitored over time for the development of any new, concerning findings.”