Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. During pregnancy, untreated maternal syphilis can be transmitted to the fetus, resulting in congenital syphilis.
Key Findings
- The U.S. Centers for Disease Control and Prevention reported in January 2026 that maternal syphilis rates rose 28% from 2022 to 2024, from approximately 280 to 360 cases per 100,000 births.
Factors Contributing to the Rise
The increase in syphilis cases in the general population is a primary driver, directly leading to more maternal syphilis. Additional factors include:
- Barriers to healthcare access and funding limitations affecting pregnant women.
- Stagnant public health funding for sexually transmitted infections (excluding HIV) at about $160 million annually, resulting in a 40% reduction in spending power adjusted for inflation.
- Proposed budget cuts for 2026 combining HIV, STI, and tuberculosis programs with a $70 million reduction.
- The COVID-19 pandemic reducing staffing and hours at safety-net clinics, limiting screening and treatment.
- Changes in sexual behaviors since the early 2000s due to improved HIV treatments, leading to decreased safer sex practices.
Stigma and Bias
Social stigma and healthcare provider biases can deter testing and treatment, especially for pregnant patients.
- Providers may assume screening is unnecessary for long-term patients in monogamous relationships.
- Patients may hesitate to disclose risky sexual behaviors or may not know about exposure through a partner's infidelity.
Barriers to Prenatal Care
One in four pregnant individuals lack first-trimester prenatal care. Barriers include:
- Race, ethnicity, transportation, economic status, rural/urban location, and insurance.
- Medicaid enrollment for pregnancy can take months, delaying syphilis screening beyond the first trimester.
Syphilis Symptoms and Stages
- Primary stage: painless ulcer at exposure site, resolves on its own.
- Secondary stage (3–6 months after exposure): flu-like symptoms, weight loss, swollen lymph nodes, non-itchy rash on chest/back ± palms/soles, hair loss, mouth lesions, hearing/vision changes.
- Latent phase: bacteria active without acute symptoms for decades.
- Tertiary phase (40–60% of untreated cases): seizures, heart defects, bone/skin growths, confusion, dementia.
Transmission and Congenital Syphilis
Bacteria cross the placenta via shared blood supply, more likely within the first year of infection but possible at any stage.
- Congenital syphilis can cause miscarriage, stillbirth, developmental delays, blindness, hearing loss, bone/tooth malformation, heart defects, and rashes.
- Symptoms may appear at birth or later (e.g., after age 2).
- Congenital syphilis is treatable with antibiotics but cannot reverse existing damage.
Treatment Options
- Syphilis is treatable with a long-acting penicillin injection.
- Non-pregnant patients without neurological symptoms can use oral doxycycline for 14–28 days.
- The long-acting penicillin injection is currently in short supply.
Prevention
Prevention relies on a combination of strategies:
- Use condoms or ensure partners are tested negative and exclusive.
- Doxycycline post-exposure prophylaxis (doxy PEP) within 72 hours of sexual activity.
- Universal screening for all pregnancies in the first trimester, third trimester, and at delivery.
- Published studies show screening rates of 80–90% for private insurance and 56–90% for Medicaid, at least once during pregnancy.