Syphilis in pregnancy

M R C O G PA R T 2 · S O S P O C K E T C A R D · K N O W L E D G E A R E A 5 – A N T E N ATA L C A R E

Syphilis in Pregnancy: Identifying and Managing a Historic Problem on the Rise Dewick L et al. Syphilis in pregnancy: identifying and managing a historic problem on the rise. TOG 2020;22:209–216. doi:10.1111/tog.12669

162% 100% 2.4 MU RISE IN UK SYPHILIS CASES 2008–18 VERTICAL TRANSMISSION RISK, PRIMARY BENZATHINE PENICILLIN G, STAT IM DOSE SYPHILIS

DO N' T-M IS S FA C TS

  1. Vertical transmission risk: primary 100% · early latent 40% · late latent 10%; can cross placenta from 14 weeks

  2. First-line treatment: benzathine penicillin G 2.4 MU IM stat (early disease); extra dose in 3rd trimester; weekly ×3 for late/unknown duration disease

  3. Macrolides no longer recommended (BASHH) – confirm true penicillin allergy via immunology before switching

  4. Jarisch–Herxheimer reaction: up to 45% of treated pregnant women, onset <24h, can trigger uterine contractions – supportive care only

  5. Treating ≥30 days before delivery is the key factor reducing congenital infection/perinatal death

  6. UK congenital cases now occurring in women screened negative at booking – offer repeat screening every 3 months if high risk (BASHH/PHE)

  7. Hutchinson's Triad = 8th nerve deafness + interstitial keratitis + notched incisors (late congenital disease)

  8. RPR/VDRL can be falsely positive in pregnancy itself; treponemal EIA/TPPA needs confirmatory 2nd test

FETAL USS FEATURES

Ascites Hepatosplenomegaly Intrahepatic calcifications Placentomegaly Fetal hydrops (severe)

ABBREVIATION KEY

WHO — World Health Organization TPHA — Treponema pallidum haemagglutination assay

STI — sexually transmitted infection RPR — rapid plasma reagin

PHE — Public Health England VDRL — venereal disease research laboratory carbon antigen test

BASHH — British Association for Sexual Health and HIV CLIA — chemiluminescent immunoassay

NICE — National Institute for Health and Care Excellence GUM — genitourinary medicine

PCR — polymerase chain reaction MSM — men who have sex with men

EIA — enzyme immunoassay IM — intramuscular

TPPA — Treponema pallidum particle agglutination assay MU — million units

Source: The Obstetrician & Gynaecologist (TOG), RCOG journal — doi:10.1111/tog.12669

Clinically reviewed by NHS obstetricians and gynaecologists

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