Stemming the Tide of Rising Congenital Syphilis in the United States: An Update and Review of the Provider Role


Aliza M. Machefsky MD1,2

1: Division of STD Prevention; Centers for Disease Control and Prevention; Atlanta, GA, USA

2: CDC Foundation; Atlanta, GA, USA

Congenital Syphilis — Reported Cases by Year of Birth and Rates of Reported Cases of Primary and Secondary Syphilis Among Females Aged 15–44 Years, United States, 2010–20191

ACRONYMS: CS = Congenital syphilis; P&S = Primary and secondary syphilis

Centers for Disease Control and Prevention. Sexually transmitted disease surveillance 2019. US Department of Health and Human Services. Accessed April 14th, 2021,

What is Syphilis?

Syphilis is an ancient and devastating sexually transmitted infection (STI), caused by the spirochete bacterium Treponema pallidum. It is transmitted by:

  • Direct contact with a syphilitic lesion during vaginal, anal, or oral sex


  • Transplacental transmission during pregnancy.1

What is Congenital Syphilis?

When a fetus or infant becomes infected with syphilis due to maternal syphilitic infection, it is called Congenital Syphilis (CS). CS can be acquired at any stage of maternal syphilis and any gestational age from a mother with untreated or inadequately treated syphilis.1 Syphilis during pregnancy is associated with:

  • Miscarriage
  • Stillbirth
  • Preterm delivery
  • Perinatal death
  • Liveborn infants who exhibit clinical manifestations of CS2 

Early Signs of CS

Early signs of CS can present anywhere from birth to the first two years of life and include:

  • Rash
  • Copious nasal discharge (known as “snuffles”)
  • Anemia
  • Thrombocytopenia
  • Hepatosplenomegaly
  • Inflammation of the long bones

Late Signs of CS

Newborn treatment of CS within the first three months of life prevents the development of late sequalae.3 Late signs appear slowly over the first 20 years of life but are more permanent and debilitating and include:

  • Bone abnormalities
  • Craniofacial abnormalities
  • Joint swelling
  • Interstitial keratitis
  • Blindness
  • Hearing loss
  • Developmental delays4, 5 

The Current Problem

CS reached a low in the United States in 2012 with 334 reported cases. However, since 2012, cases of CS have increased annually, reaching 1,870 reported cases in 2019—a 460% increase in seven years and the highest rate for the 21st century. Among infants reported with CS in 2019, 128 (6.8%) were stillborn or died during early infancy. Another 712 (38.1%) were reported with signs or symptoms of CS.6

Why CS is Preventable?

CS can be prevented by identifying and treating infected women prior to pregnancy or by adequately treating maternal infection during pregnancy with a penicillin regimen that is both appropriate for the maternal stage of syphilis and initiated at least 30 days prior to delivery.

Recommended regimens for Penicillin G in pregnancy are:

  • Early Syphilis (primary, secondary, and early latent):
    • 2.4 million units x 1 dose
  • Late or Unknown Duration Syphilis:
    • 2.4 million units x 3 at 1-week intervals
      • Optimal treatment interval: 7 days

Adequate treatment during pregnancy is 98% efficacious in preventing CS.1, 7 

Because of this, CDC recommends the following for syphilis screening in pregnancy:

  • All pregnant women should be tested for syphilis at their first prenatal visit.
  • Repeat screening for pregnant women at high risk, either because they or their partners exhibit high-risk behaviors (e.g., transactional sex, substance misuse, multiple STIs), have been in high-risk settings (e.g., people suffering from homelessness, recent incarceration), or live in high-prevalence areas, should occur at 28 weeks and at delivery in order to detect those mothers who became infected or reinfected during pregnancy.
  • Before a mother or infant has been discharged from the hospital, maternal testing should be confirmed at least once during pregnancy.  
  • Additionally, due to the high association between CS and stillbirth, all women who deliver a stillborn infant should be tested for syphilis.1

What Midwives Can Do About It?

Because CS is preventable, its resurgence points to missed opportunities for intervention—areas in which both the public health and healthcare systems can do more. Among the 1,306 reported CS cases in 2018, the most common missed opportunity nationally was:

  • Lack of timely treatment despite timely testing (30.7%)

Followed by:

  • Lack of prenatal care (28.2%)
  • Late identification of seroconversion during pregnancy (11.2%)
  • No timely syphilis testing despite receipt of timely prenatal care (8.9%)

*with variations by geographic region.8 

Helping prevent the continued rise in congenital syphilis will require your help; as women’s healthcare advocates, midwives are uniquely situated to help reduce maternal and neonatal morbidity caused by syphilis. You can learn more about the rise of congenital syphilis and what you can do to help prevent it at the upcoming ACNM 66th Annual Meeting, held virtually May 23 – 25, 2021.

1.Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recommendations and reports : Morbidity and mortality weekly report Recommendations and reports. Jun 5 2015;64(Rr-03):1-137.

2.Gomez GB, Kamb ML, Newman LM, Mark J, Broutet N, Hawkes SJ. Untreated maternal syphilis and adverse outcomes of pregnancy: a systematic review and meta-analysis. Bulletin of the World Health Organization. 2013;91(3):217-226. doi:10.2471/blt.12.107623

3.Cooper JM, Sanchez PJ. Congenital syphilis. Semin Perinatol. Apr 2018;42(3):176-184. doi:10.1053/j.semperi.2018.02.005

4.Bennett JEB, Martin J.;Dolin, Raphael. Congenital Syphilis. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases 2015.

5.Kliegman RMS, Bonita M.D.; St Geme, Joseph; Schor, Nina F Chapter 218: Congenital Syphilis Nelson Textbook of Pediatrics 20th Edition ed. 2015.

6.Centers for Disease Control and Prevention. Sexually transmitted disease surveillance 2019. US Department of Health and Human Services. Accessed April 14th, 2021,

7.Alexander JM, Sheffield JS, Sanchez PJ, Mayfield J, Wendel GD, Jr. Efficacy of treatment for syphilis in pregnancy. Obstetrics and gynecology. Jan 1999;93(1):5-8. doi:10.1016/s0029-7844(98)00338-x

8.Kimball A, Torrone E, Miele K, et al. Missed Opportunities for Prevention of Congenital Syphilis – United States, 2018. MMWR Morb Mortal Wkly Rep. Jun 5 2020;69(22):661-665. doi:10.15585/mmwr.mm6922a1