Syphilis Screening in Pregnancy

May 22, 2009 — The US Preventive Services Task Force (USPSTF) has reaffirmed its 2004recommendation to screen all pregnant women for syphilis infection.

Harms of failure to treat syphilis during pregnancy may include stillbirth, neonatal death, bone deformities, and neurologic impairment. Evidence is adequate that screening tests for syphilis can accurately detect infection. Universal screening of pregnant women for syphilis is associated with a lower proportion of infants who have clinical manifestations of syphilis infection, according to convincing observational evidence reviewed by the USPSTF.

Screening Process for and Treatment of Syphilis

The recommended screening for syphilis consists of nontreponemal tests, either the Venereal Disease Research Laboratory test or the rapid plasma reagin test. If results are positive, these should be confirmed by a fluorescent treponemal antibody absorbed test or a Treponema pallidum particle agglutination test.

Screening should be performed at the first prenatal visit in all pregnant women, as well as in the third trimester and at delivery for women at high risk.
Those at high risk include uninsured women, women living in poverty, sex workers, illicit drug users, women diagnosed with sexually transmitted diseases, and those living in communities with high syphilis morbidity.

For the treatment of syphilis during pregnancy, the Centers for Disease Control and Prevention (CDC) recommends parenteral benzathine penicillin G. Because evidence is limited regarding the efficacy or safety of alternative antibiotics in pregnancy, women who report penicillin allergies should be evaluated and desensitized to penicillin if necessary.

"Syphilis may be transmitted vertically, usually through the placenta; the risk for fetal infection increases with gestational age," write Tracy Wolff, MD, MPH, from the USPSTF, and coauthors of the accompanying evidence statement. "Vertical transmission may also occasionally occur during delivery if maternal genital lesions are present... "Although the overall rate of congenital syphilis has decreased significantly since the onset of the syphilis elimination plan in 1996, this recent increase is cause for concern, given that congenital syphilis is preventable."


source: Ann Intern Med. 2009;150:705-709, 710-716.