Summary of Recommendation and Evidence

The U.S. Preventive Services Task Force (USPSTF) recommends that physicians screen all pregnant women for syphilis infection (Table A). A Recommendation.

Rationale

Importance. Untreated syphilis during pregnancy is associated with stillbirth, neonatal death, bone deformities, and neurologic impairment.

Detection. There is adequate evidence that screening tests can accurately detect syphilis infection.

Benefits of detection and early treatment. The USPSTF found convincing observational evidence that the universal screening of pregnant women decreases the proportion of infants with clinical manifestations of syphilis infection.

Harms of detection and early treatment. Screening and treatment may result in potential harms, including false-positive results that require clinical evaluation, unnecessary anxiety to the patient, and harms of antibiotic use. However, the USPSTF concluded that the harm from screening is no greater than small.

USPSTF assessment. The USPSTF concludes with high certainty that the net benefit of screening is substantial for pregnant women.

Clinical Considerations

• Patient population. This recommendation applies to pregnant women.

• Assessment of risk. Pregnant women who are at increased risk of syphilis infection include uninsured women, women living in poverty, sex workers, illicit drug users, and women living in communities with high syphilis morbidity.¹ The prevalence of syphilis infection differs by region (it is higher in the southern United States and in some metropolitan areas than in the United States as a whole) and by ethnicity (it is higher in Hispanic and black populations than in the white population). Persons in whom sexually transmitted diseases have been diagnosed may be more likely than others to engage in high-risk behavior, which places them at increased risk of syphilis.

• 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 test.

• Treatment. The Centers for Disease Control and Prevention (CDC) has outlined appropriate treatment of syphilis in pregnancy. In its 2006 sexually transmitted disease treatment guidelines, the CDC recommends parenteral penicillin G benzathine for the treatment of syphilis in pregnancy. Evidence on the effectiveness or safety of alternative antibiotics in pregnancy is limited; therefore, women who report penicillin allergies should be evaluated and, if present, desensitized and treated with penicillin. Because the CDC updates these recommendations regularly, physicians are encouraged to access the CDC Web site to obtain the most up-to-date information (http://www.cdc.gov/std/treatment/).

• Screening intervals. All pregnant women should be tested at their first prenatal visit. For women in high-risk groups, many organizations recommend repeat serologic testing in the third trimester and at delivery. Most states mandate that all pregnant women be screened at some point during pregnancy, and many mandate screening at the time of delivery. Follow-up serologic tests should be obtained after treatment to document decline in titers. To ensure that results are comparable, follow-up tests should be performed using the same nontreponemal test that was used initially to document the infection (i.e., VDRL or RPR test).

• Useful resources. The USPSTF has made recommendations on screening for other sexually transmitted diseases in pregnancy, including gonorrhea, chlamydial infection, hepatitis B, herpes, and human immunodeficiency virus. These recommendations are available on the USPSTF Web site (http://www.preventiveservices.ahrq.gov).

Discussion

In 2004, the USPSTF reviewed the evidence on screening for syphilis in pregnant women. In 2008, the USPSTF performed a targeted literature review and determined that the net benefit of screening pregnant women continues to be well established.² This literature update included a search for new and substantial evidence on the benefits of screening, harms of screening, and harms of treatment with penicillin. The USPSTF found no new substantial evidence that could change its recommendation, and therefore reaffirms its recommendation to screen all pregnant women for syphilis. The previous recommendation statement and evidence report, as well as the 2008 summary of the updated literature search, can be found at http://www.preventiveservices.ahrq.gov.

Recommendations from Other Groups

The American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG) recommend that all pregnant women be screened for syphilis with serologic testing at the first prenatal visit, after exposure to an infected partner, and at the time of delivery.³ They recommend that pregnant women who are considered at high risk of acquiring syphilis should also be tested at the beginning of the third trimester. The AAP and the ACOG advise using a nontreponemal screening test initially (RPR or VDRL test), followed by a confirmatory treponemal antibody test.³ The CDC recommends that all pregnant women be screened for syphilis with serologic testing at the first prenatal visit.⁴ Pregnant women who are at high risk, who live in areas with a high prevalence of syphilis, who have not been previously tested, or who have had a positive serology test for syphilis during the first trimester should be screened again early in the third trimester (28 weeks) and at the time of delivery. The American Academy of Family Physicians (AAFP) strongly recommends that all pregnant women be screened for syphilis.⁵ The AAFP also advises screening with serologic testing at the first pre-natal visit, with repeated serologic testing at 28 weeks, and at the time of delivery for pregnant women who are at high risk.