Syphilis During Pregnancy
Diagnostic Considerations
Seropositive pregnant women should be considered infected unless an adequate treatment history is documented clearly in the medical records and sequential serologic antibody titers have declined appropriately for the stage of syphilis. In general, the risk for antepartum fetal infection or congenital syphilis at delivery is related to the stage of syphilis during pregnancy, with the highest risk occurring with the primary and secondary stage. Quantitative maternal nontreponemal titer, especially if >1:8, might be a marker of early infection and bacteremia. However, risk for fetal infection is still significant in pregnant women with late latent syphilis and low titers. Pregnant women with stable, serofast low antibody titers who have previously been treated for syphilis might not require additional treatment; however, rising or persistently high antibody titers might indicate reinfection or treatment failure, and treatment should be considered.
If a treponemal test (e.g., EIA or CIA) is used for antepartum syphilis screening, all positive EIA/CIA tests should be reflexed to a quantitative nontreponemal test (RPR or VDRL). If the nontreponemal test is negative, then the results are considered discrepant and a second treponemal test (TP-PA preferred) should be performed, preferably on the same specimen. If the second treponemal test is positive, current or past syphilis infection can be confirmed. For women with a history of adequately treated syphilis who do not have ongoing risk, no further treatment is necessary. Women without a history of treatment should be staged and treated accordingly with a recommended penicillin regimen. If the second treponemal test is negative, the positive EIA/CIA is more likely to represent a false-positive test result in low-risk women with no history of treated syphilis (400). If the woman is at low risk for syphilis, lacks signs or symptoms of primary syphilis, has a partner with no clinical or serologic evidence of syphilis, and is likely to follow up, repeat serologic testing within 4 weeks can be considered to determine whether the EIA/CIA remains positive or if the RPR/VDRL or the TP-PA becomes positive. If both the RPR and TP-PA remain negative, no further treatment is necessary. If follow-up is not possible, women without a history of treated syphilis should be treated according to the stage of syphilis.