Congenital Syphilis - Investigation and Treatment of Infants Born to Mothers with a History of Syphilis

Publication: 01/03/2007  --
Last review: 15/10/2019  
Next review: 15/10/2022  
Clinical Guideline
ID: 955 
Supported by: Maternity/ GUM congenital infection MDT
Approved By: Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2019  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Congenital Syphilis - investigation and treatment of infants born to mothers with a history of syphilis

Aims and Objectives

To provide evidence-based recommendations for appropriate diagnosis, investigation and management of congenital syphilis.

  • To prevent the vertical transmission of syphilis.
  • To encourage effective and timely treatment of high risk infants
  • To encourage a rational and targeted approach to follow up of infants with no clinical signs of syphilis

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Syphilis is caused by a spirochete Treponema pallidum. Maternal syphilis infection has increased substantially in the last decade. In 2011 1 in 650 women screened antenatally were positive (0.15%) 46% had been fully treated in the past, 23% false postives and 21% required treatment. Syphilis can be transmitted across the placenta at any stage of pregnancy. Co-existence of HIV infection increases the risk. The risk of vertical transmission is about 20% in untreated syphilis. Antenatal screening and treatment of infected mothers is the mainstay of prevention and reduces the risk of transmission by 97%. If maternal treatment is given before 20 weeks T pallidum can be eradicated (1). There is little, if any, evidence to suggest that women with prior adequately treated syphilis can transmit during a subsequent pregnancy unless they have been reinfected (2). Overall only 10 babies/year in UK acquire congenital syphilis. In recent years the incidence of infectious syphilis in the UK has increased dramatically. There was a 20% increase in diagnoses between 2016 and 2017, and a 148% increase relative to 2008 and there are several reports of cases of congenital syphilis.3-4

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Diagnosis of Congenital Syphilis

60% of infected babies are asymptomatic at birth. Signs that may be present are:

  • Skin: Maculopapular or bullous rash over back, buttocks, soles and palms (which may be bronze or bright red). Desquamation of skin.
  • Nasal: Rhinitis and snuffles (from 1 week) - clear becoming purulent and blood-stained
  • Laryngitis with hoarse cry
  • Mucous patches on lips, tongue, anus.
  • Hepatosplenomagaly (90%)
  • Generalised lymphadenopathy (50%)
  • Blood: Haemolytic anaemia, thrombocytopenia
  • Jaundice- conjugated or unconjugated
  • Failure to thrive
  • Rarely: peri-osteitis, meningitis, hydrops

Confirmation of congenital syphilis.
If a baby is T.pallidum IgM antibody Positive (confirmed on a second specimen) then congenital syphilis is confirmed.
If a baby is IgM negative, but has an RPR titre ≥ 4 times the maternal RPR titre (confirmed on a second specimen) then congenital syphilis is confirmed.

Treatment of congenital syphilis is described in the treatment section below.

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Investigations in syphilis can be confusing! It is further complicated by the fact that in infants maternal IgG crosses the placenta and will be detected in infant blood for up to 18 months, leading to babies appearing to have positive results. Note that to avoid maternal contamination, samples must not be taken from umbilical blood. This section provides an overview of the investigations.

  1. Direct testing of infected lesions: Treponema pallidum may be visualised using dark field microscopy or PCR methods.
  2. Serology: Treponema-specific and non-specific tests are used.

Treponema specific test: these become positive soon after infection but often remain positive despite adequate treatment. They are used to confirm positive screening tests but cannot be used to monitor response to treatment. These can remain positive in baby for up to 18 months due to passive transfer of IgG. Tests used in LTHT include

  • TPPA- Treponema pallidum particle agglutination assay
  • Syphilis EIA- an enzyme assay that detects both IgG and IgM
  • T. pallidum IgM EIA- only detects IgM.

Non-treponemal tests: These are quantitative (expressed as a titre) and can be used for screening and to monitor response to treatment. They can take up to 2 weeks to become positive. Remember that the higher the titre number, the more times the sample has been diluted and still given a positive result- in other words the more antibody is present. Hence 1 in 256 is more reactive than 1 in 2 or “neat”. These tend to become negative in uninfected babies within 3-6 months of birth. In LTHT the non-specific test used is:

  • RPR (Rapid plasma regain test)

All babies born to mothers with any history of syphilis should be examined. Unless they have been treated and cured prior to this pregnancy they should also have a Treponemal EIA followed by RPR and specific T.pallidum IgM and TPPA assay performed at birth (see Investigations for explanation of tests). It is very important to put as much maternal history on the microbiology request form as possible- e.g. date of syphilis diagnosis and any treatment received.

All babies who are screened should be notified to the congenital infection clinic using the attached form (even if you dont think they need follow up- it allows us to chase results and audit follow up)

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Management and treatment of different risk groups

Highest risk group: confirmed congenital syphilis:
  • Repeat quantitative RPR, TPPA and IgM to confirm diagnosis and establish a baseline titre (but do not delay treatment). It is very important that the RPR and TPPA should be performed on the infant and the mother at the same time, to allow comparison of titres.
  • Full blood count
  • Liver function tests
  • Urea and electrolytes
  • CSF (cell count, protein and T. pallidum antibodies, using RPR)
  • X-ray long bones
  • Ophthalmic assessment
  • Dark field microscopy or T.pallidum PCR of fluid from any bullous lesions or discharge (consult with microbiology before obtaining sample).

Treat with Benzylpenicillin 50mg/kg i.v. 12 hourly for the first 7 days of life and 50mg/kg 8 hourly thereafter for a total of 10 days. This is the preferred regime. If there is no i.v. access procaine penicillin 50mg/kg can be given i.m. once a day for 10 days. If more than 24 hours treatment is missed the whole course should be repeated.

Follow up of confirmed infection: See at 1,2,3 and 6 months and then 6 monthly until RPR is negative. Note TPPA and other specific tests may stay positive despite treatment.

At each follow up check:

  • RPR (if increasing 4 fold suggests treatment failure)
  • TPPA
  • T. pallidum IgM

Any older siblings will require examination and serology to exclude infection.
Once > 6 months old and RPR becomes negative the baby can be discharged (even if TPPA not negative)

High risk group: Babies whose mothers had any of the following:

  • untreated syphilis in this pregnancy
  • received treatment less than 4 weeks before delivery
  • were treated with non-penicillin regimes (do not always cross placenta)
  • Indeterminate: Confirmed syphilis in past with no evidence of adequate treatment available (check with GUM if not sure)

These babies should all be examined, investigated and treated as if they have congenital syphilis, even if they have no signs and T. pallidum IgM is negative and RPR is < 4 times mothers titre.
Follow up: follow up as for confirmed syphilis (even if baby fully treated after birth they still need follow up).
Once RPR becomes negative the baby can be discharged (even if TPPA not negative)

Moderate risk group: Mothers with syphilis in this pregnancy that has been adequately treated more than 4 weeks before delivery, with a confirmed response and no evidence of re-infection. (check with GUM if not sure)
  • Examine for signs of congenital syphilis
  • Do not do LP, X-rays or eye exam unless clinically indicated
  • Check RPR and IgM at birth. Discharge home if T. pallidum IgM negative.
  • Follow up at 3 months and 6 months. At each visit check: RPR
  • If RPR rises to 4 times mother’s titre then re-assess for congenital syphilis.
  • Once RPR becomes negative baby can be discharged
Lowest risk group: Past history of maternal syphilis that was adequately treated before this pregnancy and mothers syphilis serology has remained low (RPR <1:4) and mother has not required treatment in this pregnancy.

Examine for signs of congenital syphilis as part of the routine newborn baby check.

These babies do not need any blood screening at or after birth.
Baby can be discharged home and does not need any follow up.

(This is a new policy from June 2015 in line with new national guidance. If mothers have had a previous baby in Leeds they may be expecting blood tests after birth. Provided they meet the criteria above they can be reassured that the baby does not need testing as they have been adequately treated prior to pregnancy).

Follow up:

  • If mother cured before this pregnancy- no screening or follow up



Record: 955

To provide evidence-based recommendations for appropriate diagnosis, investigation and management of congenital syphilis.

  • To prevent the vertical transmission of syphilis.
  • To encourage effective and timely treatment of high risk infants
  • To encourage a rational and targeted approach to follow up of infants with no clinical signs of syphilis
Clinical condition:

Congenital syphilis

Target patient group: Neonates
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

New reference

British association of sexual health
UK National Guidelines on the Management of Syphilis 2015 (Draft)

References and Evidence levels:
This guideline is based on Grade C evidence based on the USA CDC protocol (3). The GUM / Pregnancy MDT has concluded that the previous UK guidance (5) is inappropriately over-cautious recommending repeated testing of low risk babies and leads to long follow up due to use of IgG based specific treponemal tests that reflect passive transfer of maternal antibody.

  1. Nathan L, Bohman VR, Sanchez PJ, Leos NK, Twickler DM, Wendel GD Jr. In utero infection with Treponema pallidum in early pregnancy. Prenat Diagn 1997;17:119-123
  2. Peterman TA, Newman DR, Davis D, Su JR. Do women with persistently negative nontreponemal test results transmit syphilis during pregnancy? Sex Transm Dis 2013;40:311-315
  3. Martina Furegato, Helen Fifer, Hamish Mohammed, Ian Simms, Paul Vanta, Sharon Webb, Kirsty Foster, Margaret Kingston, André Charlett, Bhavita Vishram, Claire Reynolds, Noel Gill, Gwenda Hughes. Factors associated with four atypical cases of congenital syphilis in England, 2016 to 2017: an ecological analysis. Euro Surveill. 2017 Dec 7; 22(49): 17-00750
  4. Simms I et al, A brief recent history of the epidemiology of congenital syphilis in the United Kingdom. Int J STD & AIDS, 2018. 29(11): p. 1110-1119
  5. Centers for Disease Control and Prevention 2010 STD Treatment Guidelines: Congenital syphilis
  6. Kingston M, French P, Higgins S, et al. UK national guidelines on the management of syphilis 2015. Int J STD AIDS. 2016;27:421-46Chang SN, Chung K-Y, Lee M-G, Lee JB. Seroreversion of the serological tests for syphilis in the newborns born to treated syphilitic mothers. Genitourinary Medicine 1995;71:68-70
  7. Cross A, Luck S, Patey R, Sharland M, Rice P, Chakraborty R. Syphilis in London circa 2004: new challenges from an old disease. Arch Dis Child 2005;90:1045-1046
  8. Le Doare K, Gannon H, Handforth J. Missed opportunities to treat: syphilis in pregnancy. Sex Transm Infect 2012;88:594
  9. Garley J. Management of positive antenatel syphilis serology in genitourinary medicine. Int J STD AIDS 2013;24(Suppl 1):P63

A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

Approved By

Clinical Guidelines Group

Document history

LHP version 2.0

Related information

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