Syphilis in pregnancy

Question 1

Natural history of infection?

Answer 1

Primary syphilis - ulcer or chancre stage
Secondary - systemic dissemination
Early latent - up to 2 years
Late latent - from 2 years
Tertiary syphilis - symptomatic later syphilis (gummas, CVS and neurological involvement)

Question 2

Primary syphilis

Answer 2

Presents with painless ulcer, well defined, and indurated base
Generally 3 weeks post infection

Question 3

Secondary syphilis

Answer 3

Constitutional symptoms (malaise, fever, headache, LN), rash, alopecia, condylomata lata, cranial nerve palsies, meningitis, hepatitis)
Time 6 weeks post infection

Question 4

Latent syphilis

Answer 4

Asymptomatic but would test positive

Question 5

Tertiary syphilis

Answer 5

One+ years after infection, neurosyphilis, CVS, skin lesions

Question 6

What adverse outcomes occur with syphilis in pregnancy?

Answer 6

Miscarriage, stillbirth, IUGR, LBW, PTB, neonatal death, SGA, congenital syphilis (risk high in the first 4 years of infection, 100% for primary and secondary, and 80% for early latent, 10% for late latent, 1-2% if treated during pregnancy)
Note: infection generally haematogenous spread

Question 7

What is the pathogenous of congenital syphilis?

Answer 7

Occurs due to immune response to treponema pallidum. Host immune response, ie doesn’t occur until after 20 weeks when fetal immune response present

Question 8

USS features of congenital syph?
Clinical features of early CS (within 2 years of age)
Late CS features?

Answer 8

Hepatosplenomegaly, placentomegaly, polyhydramnios, ascites, elevated MCA PSV, long bone abnormalities

Similar to above
Radiographic bone changes
LN
Jaundice
Rash
Anaemia
Hepatitis
Resp distress
Fever
Failure to thrive, SGA

Deformation of bones
Deformation of teeth
Keratitis
Neurosyphilis
Sensorineural hearing loss

Question 9

How do you diagnose syphilis?

Answer 9

Treponemal
- Enzyme immunoassay (EIA) first test, if negative nil further, if positive further reflect testing
- Treponemal pallidum particle agglutination (TPPA) (positive if current or past syphilis)

Non-treponemal
- Rapid plasma reagin (RPR) titre (titres should decrease if treated, be non-reactive in past treated, late latent or very early infection)

2 titre or 4 fold decline after treatment indicated adequate treatment
Fetal titre 4 fold or 2 dilution higher than maternal is bad
Con syphilis can be excluded if fetal titre negative at 6months (TPPA can be positive from maternal antibodies)

Question 10

Management of maternal syphilis in pregnancy

Answer 10

Referral to ID or sexual health
ESR notification (by treating doctor)
MDT input
Social worker
Full STI screen for all the others
Assessment and staging - need to decide if primary/secondary etc
Fetal USS through MFM if >20 weeks
Admit for treatment for Jarisch-Herxheimer Reaction
Treat all sexual contacts and older children test

Treatment
- Early syphilis (up to 2 years) in T1 or 2 Benzathine benzylpenicillin tetrahydrate 2400,000units/4.6ml IM as a single dose (note same antibiotics for RF)
T3 = 2 doses day 1 and 8

• Late syphilis
  Bezathine benzylpenicillin three doses, 1, 8, 15
  Assume late if unsure

Neurosphilis
- Benzylpenicillin sodium (pen G) 1.8g-2.4g IV every 4hours for 10-14 days

FU RPR titres 28-32 weeks and immediately following birth

Question 11

What increases the risk of fetal treatment failure?

Answer 11

Mat treatment <30 days before birth
Primary or secondary
High RPR
Fetal USS abnormalities
Treatment with non penicillin agent
Preterm birth

Question 12

Other things

Answer 12

Send placenta for swabs and histology
Okay to BF