Screening for Syphilis Infection in Pregnant Women: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Abstract

Importance: The incidence of syphilis and congenital syphilis in the United States has increased after reaching historic lows in the early 2000s.

Objective: To systematically review literature on the effectiveness and harms of screening for syphilis in pregnancy and the harms of penicillin treatment in pregnancy to inform the US Preventive Services Task Force.

Data sources: MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant English-language literature, published from January 1, 2008, to June 2, 2017. Ongoing surveillance was conducted through November 22, 2017.

Study selection: Studies conducted in countries categorized as "high" or "very high" on the Human Development Index that explicitly addressed 1 of 3 a priori-defined key questions.

Data extraction and synthesis: Independent critical appraisal and data abstraction by 2 reviewers. Data from included studies were narratively synthesized without pooling data.

Main outcomes and measures: Incidence of congenital syphilis; any harms of screening or penicillin treatment in pregnancy.

Results: Seven studies in 8 publications were included. One observational study evaluated the implementation of syphilis screening in pregnancy in 2 441 237 women in China. From 2002 to 2012, screening for syphilis in all pregnant women increased from 89.8% to 97.2%, and the incidence of congenital syphilis decreased from 109.3 to 9.4 cases per 100 000 live births. Five studies (n = 21 795) evaluated the false-positive findings of treponemal tests and 1 study (n = 318) evaluated the false-negative findings of nontreponemal tests. These studies found that false-positives with treponemal-specific enzyme or chemiluminescent immunoassays were common (46.5%-88.2%), therefore warranting reflexive (automatic confirmatory) testing for all positive test findings. One study (n = 318) found no false-negatives with treponemal tests, and 1 study (n = 139) demonstrated the prozone phenomenon (false-negative response from high antibody titer) with rapid plasma reagin screening using undiluted samples (2.9%). No studies were identified for harms of penicillin in pregnancy.

Conclusions and relevance: Screening for syphilis infection in pregnant women is associated with reduced incidence of congenital syphilis, and available evidence supports the need for reflexive testing for positive test results.