Syphilis in gynaecology and pregnancy

Definition

• Syphilis is a sexually transmitted infection caused by Treponema pallidum; the organism can be transmitted across the placenta to the fetus and cause congenital syphilis.

Classification

• Early syphilis (up to one year after infection) comprises primary and secondary syphilis, late syphilis (from one year) tertiary syphilis and neurosyphilis; asymptomatic latent phases may occur in between.

Occurrence & epidemiology

Epidemiology

• In Germany more than 90% of infections are diagnosed in men; the rise observed since 2010 is mainly due to infections among men who have sex with men.
• Among women, the 25 to 29 age group is most often affected; congenital syphilis is an isolated event in Germany (one to six cases per year since 2001).

Aetiopathogenesis

Aetiology and risk factors

• Transmission to the fetus is possible at any stage of pregnancy and any stage of maternal syphilis; it depends on the treponemal concentration in maternal blood, is more likely the more recent the infection, and reaches up to 100% when infection occurs during pregnancy.
• Most pregnant women in whom syphilis is diagnosed are in the latent stage.

Clinical features

Clinical features and complications

• In the primary stage a painless, indurated ulcer (chancre) develops with regional lymphadenopathy; in women the labia are frequently affected.
• The secondary stage begins 4–10 weeks after infection with generalised lymphadenopathy and a rash that characteristically also involves the palms and soles.
• In its natural course, intrauterine infection leads to miscarriage, stillbirth, preterm birth or death shortly after birth in about 30–40%; about 50–60% of infected infants appear normal at birth, but most become ill within the first 8 months of life.

Diagnosis

• Diagnosis is usually serological: TPHA or TPPA serve as screening tests and usually become positive 2–3 weeks after infection; a positive screening test is confirmed, for example, with the FTA-ABS test.
• Cardiolipin antibodies and treponema-specific IgM antibodies are used to assess activity; direct detection from primary lesions is possible by darkfield microscopy or PCR.

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Further reading (selection)

1. StatPearls: Congenital and Maternal Syphilis (NCBI Bookshelf)
2. RKI guide for physicians: Syphilis (Robert Koch Institute, German)

Cross-references