From the Guidelines
Pregnant women should be screened for syphilis at their first prenatal visit, with additional testing at 28 weeks and delivery for women at high risk or in high-prevalence areas. The recommended treatment for syphilis during pregnancy is penicillin G, specifically benzathine penicillin G 2.4 million units administered intramuscularly as a single dose for early syphilis (primary, secondary, or early latent) 1. For late latent syphilis or syphilis of unknown duration, the regimen is benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks. Penicillin is the only proven effective treatment during pregnancy, so women with penicillin allergies should undergo desensitization followed by penicillin treatment rather than using alternative antibiotics 1.
Screening Tests
Nontreponemal tests commonly used for initial screening are the Venereal Disease Research Laboratory (VDRL) test or the rapid plasma reagin (RPR) test. These are typically followed by a confirmatory fluorescent treponemal antibody absorbed test or Treponema pallidum particle agglutination (TPPA) test 1.
Treatment and Follow-up
Treatment should be initiated immediately after diagnosis to prevent congenital syphilis transmission to the fetus. After treatment, follow-up serologic testing is recommended at 28-32 weeks gestation and at delivery to assess treatment response. Pregnant women treated for syphilis may experience the Jarisch-Herxheimer reaction (fever, chills, headache) within 24 hours of treatment, which can cause fetal distress or premature labor, so monitoring may be advisable, particularly for women in the latter half of pregnancy.
Key Considerations
- All pregnant women should be tested at their first prenatal visit.
- Women in high-risk groups should have repeated serologic testing in the third trimester and at delivery.
- Follow-up tests should be performed using the same nontreponemal test used initially to document the infection. The USPSTF and CDC guidelines support these recommendations, emphasizing the importance of screening and prompt treatment to prevent adverse outcomes in pregnancy 1.
From the FDA Drug Label
Patients being treated for gonococcal infection should have a serologic test for syphilis before receiving penicillin. All cases of penicillin treated syphilis should receive adequate follow-up including clinical and serological examinations. The recommended follow-up varies with the stage of syphilis being treated. See CDC recommendations.
The FDA drug label recommends syphilis testing for patients being treated for gonococcal infection before receiving penicillin, and adequate follow-up for patients treated for syphilis, but it does not provide specific recommendations for syphilis testing in pregnant women. However, it mentions that pregnant women should only be treated with penicillin if clearly needed, and the label refers to CDC recommendations for follow-up, which may include guidelines for pregnant women. 2
From the Research
Syphilis Testing Recommendations for Pregnant Women
- The Centers for Disease Control and Prevention (CDC) recommends that all pregnant women be screened for syphilis early in pregnancy, with additional screenings for women at high risk of infection 3, 4.
- Women at increased risk of syphilis, such as those with a history of sexually transmitted infections, should be screened again in the third trimester and at delivery 3.
- The American College of Obstetricians and Gynecologists (ACOG) also recommends universal screening for syphilis in pregnancy, with consideration of additional screenings for high-risk women 4.
Importance of Rescreening
- Rescreening for syphilis in the third trimester is important for detecting new infections and preventing congenital syphilis 3, 5.
- A study found that rescreening in the third trimester identified new cases of syphilis that would have been missed if only initial screening was performed 3.
- However, another study found that the prevalence of syphilis was low in their obstetric population, and rescreening in the third trimester may not be necessary in all cases 5.
Barriers to Screening
- Despite recommendations for universal screening, some studies have found that screening rates for syphilis in pregnancy are lower than expected, particularly among high-risk women 4, 6.
- Barriers to screening include lack of access to prenatal care, inadequate provider knowledge, and institutional factors 4, 6.
- Linking Medicaid claims data to surveillance data can help improve detection of previous sexually transmitted infections and increase screening rates 4.
Treatment and Prevention
- Prompt treatment of syphilis in pregnancy is essential for preventing congenital syphilis and other adverse outcomes 7.
- The recommended treatment for syphilis in pregnancy is penicillin G benzathine, administered in two doses at a 5-day interval 7.
- Encouraging women to attend antenatal care early in their pregnancy is crucial for managing pregnancy-related problems, including syphilis 7.