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  • Untreated syphilis can cause many harms to adults and to fetuses during pregnancy
  • An Alberta study found that 314 fetuses were exposed to syphilis in the womb, with 16 stillbirths
  • Researchers call for enhanced access to syphilis screening and treatment during pregnancy

An epidemic of syphilis is occurring across Canada. The initial symptoms of syphilis—a sore or chancre on or inside the genitals or other parts of the body—may be mild or go unnoticed. The germs that cause syphilis (called treponemes) quickly spread from the site of first contact. These germs can attack nerves in the ears (causing hearing loss) and eyes (causing loss of vision) and can cause injury to vital organs, including the brain, bones, heart and circulatory system, liver and kidneys. Syphilis during pregnancy can harm the fetus. Symptoms of syphilis can mimic many other diseases; however, syphilis can be easily diagnosed with a simple blood test. Most people can recover from syphilis with a single course of antibiotic therapy.

In Alberta

A team of researchers in Edmonton, Alberta, has been accessing databases to document and understand factors associated with syphilis-related stillbirths. The team conducted its study between January 2015 and June 2021.

During this time, 314 fetuses were exposed to syphilis in the womb. A total of 16 pregnancies (5%) ended in stillbirths.

According to the researchers, stillbirths occurred “due to a failure to treat syphilis in pregnancy.” The researchers called for innovative practices to reach people experiencing barriers to care so that syphilis can be diagnosed and treated as early as possible during the course of pregnancy.

Focus on pregnancy

In the study, on average, women were 30 years old when the stillbirths occurred. All had previous pregnancies. Some of the women were co-infected with chlamydia, gonorrhea and/or hepatitis C virus (HCV). None of them had hepatitis B virus (HBV) or HIV.

Distribution of stillbirths in Edmonton over time

The distribution of stillbirths due to syphilis over the course of the study was as follows:

  • 2015 to 2017 – no cases
  • 2018 – 1 case
  • 2019 – 6 cases
  • 2020 – 7 cases
  • 2021 – 2 in the first half of the year (data are pending for the remainder of the year)

Syphilis screening

Researchers stated that their investigation revealed that “only five of the 16 females (31%) had syphilis [screening] performed as part of routine prenatal bloodwork before the fetus died.” Also, routine fetal ultrasound scans were done prior to the death of the fetus in only two cases. In both cases the ultrasound scans were normal.

Analysis of stillbirths

Samples of the placenta or umbilical cord were screened for the genetic material of treponemes in all 16 cases. Thirteen of the 16 fetuses tested positive—these were classed as confirmed syphilitic stillbirths. The remaining stillbirths were classed as probable syphilitic stillbirth.

Treatment for syphilis

The treatment of choice for syphilis is benzathine penicillin. However, as mentioned earlier, many women were not screened for syphilis during pregnancy and therefore did not receive treatment. Even in cases where such screening occurred, treatment was given too late in the course of pregnancy, as the fetus had already died, or a case of unrecognized reinfection had occurred and no treatment was provided.

Preventing syphilis in pregnancy

To prevent stillbirths, regular screening and treatment of people is needed, ideally before pregnancy occurs. Once pregnancy occurs, early screening and treatment is needed to prevent fetal injury and demise.

In Alberta and across Canada, screening for syphilis is routine during prenatal care, particularly during the first visit. The screening and treatment are provided at no cost to the patient.

The Edmonton researchers cited previous studies and stated that issues such as “poverty and substance use are key factors in the current syphilis crisis [in Canada].” They added that “there is a need for innovative methods to reach persons who experience barriers in accessing care.”

Alert to the absence of syphilis screening

The researchers encourage a range of healthcare providers to facilitate syphilis screening during pregnancy. They noted that, in Alberta, “in a newly launched clinical information system, flagging of pregnant females without syphilis screening in their current pregnancy is underway in emergency departments. All positive results will be followed by provincial Sexually Transmitted Infection services to expedite the administration of penicillin, when appropriate.”

The researchers also noted that ultrasound technicians who are conducting prenatal scans will be alerted if there is no record of syphilis screening.

The deployment of syphilis test kits by what the researchers called “outreach services” would help make syphilis screening and treatment more likely accessible at the same visit.

Further innovations and likely investment are needed if success against the syphilis epidemic is to be achieved and sustained.

—Sean R. Hosein


Syphilis ResourcesCATIE

Alberta researchers find high rates of hepatitis C virus and syphilis co-infection during pregnancyCATIE News

Rapid combined syphilis-HIV testing found accurate and useful in an Alberta studyCATIE News

Alberta study underscores the importance of syphilis testing in people who use stimulantsCATIE News


  1. Robinson JL, Donovan A, Gratrix J, et al. Case series of stillbirths due to syphilis in Edmonton, Alberta, Canada. Sexually Transmitted Diseases. 2023; in press
  2. Peeling RW, Mabey D, Xiang-Shen C, et al. Syphilis. Lancet. 2023; 403(10398):336-346.  
  3. Round JM, Plitt SS, Eisenbeis L, et al. Examination of care milestones for preventing congenital syphilis transmission among syphilis-infected pregnant women in Alberta, Canada: 2017-2019. Sexually Transmitted Diseases. 2022 Jul 1;49(7):477-483. 
  4. Gratrix J, Karwacki J, Eagle L, et al. Outcomes of infectious syphilis in pregnant patients and maternal factors associated with congenital syphilis diagnosis, Alberta, 2017-2020. Canada Communicable Disease Report. 2022 Feb 24;48(2-3):61-67.