Syphilis in Pregnancy

Description

Diagnosis

General measures

Medicine treatment

Referral (baby)

---

O98.1

DESCRIPTION

A sexually transmitted infection with many manifestations that has a latent phase and may be asymptomatic in pregnant women. It is caused by the spirochaete, T pallidum. Vertical transmission to the foetus occurs in up to 80% of cases in untreated mothers. Untreated maternal syphilis may lead to miscarriage, stillbirth, non-immune hydrops fetalis, or congenital syphilis in the newborn.

DIAGNOSIS

• All pregnant women should have a syphilis test at the first booking visit.
• Women who booked in the first trimester and tested negative should have a repeat test done around 32 weeks' gestation.
• Diagnosis is made by positive serology. Clinical signs and symptoms are most recognisable in secondary syphilis. These include rash on palms of the hand and/or soles of the feet; and condylomata lata on genital areas.
• There are 2 types of diagnostic tests:

Specific treponemal test (e.g. TPAb//TPHA/FTA-ABS):

Non-treponemal test (e.g. RPR):

- Specifically diagnoses syphilis - Available as rapid on-site finger prick syphilis tests or laboratory based assays. - Dual HIV/syphilis rapid on-site test may be used when HIV status is negative/unknown. - Once positive, a specific treponemal test generally remains positive for life, and therefore the presence of specific treponemal antibodies cannot differentiate between current and past infections. - A person with previously successfully treated syphilis will retain lifelong positive specific treponemal test results. - Thus a positive test should be immediately followed by an RPR test to confirm active disease; however treatment can be started while awaiting the RPR result.

The RPR can be used: - To determine if the patient's syphilis disease is active or not, - To measure a successful response to therapy (at least a fourfold reduction in titre, e.g. 1:256 improving to 1:64), or - To determine a new re-infection. Note: - False RPR positive reactions may occur, notably in patients with connective tissue disorders (these are usually low titre <1:8). For this reason, positive RPR results should be confirmed as due to syphilis by further testing of the serum with a specific treponemal test; if the specific test result cannot be obtained the same day, start treatment while awaiting the result. - If specific treponemal test e.g. TPAb is performed first and gives a positive result, serum can be further tested for RPR to determine the presence of active syphilis (reverse testing algorithm). - Some patients, even with successful treatment for syphilis, may retain life-long positive RPR results at low titres (≤1:8), which does not change by more than one dilution difference over time (so-called serofast patients).

 

GENERAL MEASURES

• Encourage partner notification and treatment after confirming the diagnosis.
• Provide counselling and promote HIV testing.
• Educate on treatment adherence.
• Promote condom use.

MEDICINE TREATMENT

Pregnant woman

• Benzathine benzylpenicillin, IM, 2.4 MU weekly for 3 weeks.
  • Reconstitute with 6 mL of lidocaine 1% without adrenaline (epinephrine).
  • Follow up at 3 months after the last injection to confirm a fourfold (i.e. 2 dilution) reduction in RPR titres, provided the initial titre was ≥ 1:8. If initial titre < 1:8, further reductions may not occur (serofast reaction).

LoE:IVb²⁷

Severe penicillin allergy:

Z88.0

Refer for in-patient penicillin desensitisation.

Newborn baby

If baby asymptomatic, well and mother not fully treated > 1 month before delivery, give:

• Benzathine benzylpenicillin (depot formulation), IM, 50 000 units/kg as a single dose into the lateral thigh.

---

Caution:
Benzathine benzylpenicillin (depot formulation) must never be given intravenously.

---

REFERRAL (BABY)

• Mother was not treated
• Mother has received < 3 doses of benzathine benzylpenicillin
• Mother delivered within 4 weeks of commencing treatment
• Baby has any of the following:
  • Hepatosplenomegaly
  • Pseudoparesis
  • Snuffles
  • Oedema
  • Jaundice
  • Anaemia
  • Purpura
  • Desquamative rash (especially involving palms and soles)

Click here to access the pdf.

---

Standard Treatment Guidelines and Essential Medicines List for South Africa, Primary Healthcare, 2025-9_Version 1.0_26 March 2026

Chapter 6: Obstetrics and Gynaecology_6.4.4 Syphilis in Pregnancy