Perinatal Infections Flashcards
What problems does sustained pyrexial illness cause in 1st trimester?
Miscarriage
NTD
What problems does sustained pyrexial illness cause in T2/T3?
Preterm labour
Fetal death
What is the most common cause of fetal or neonatal death?
Preterm labour
What are the two most common bacterial infections in pregnancy?
UTI, chorioamnionitis
What are the two most common causes of preterm labour?
Chorioamnionitis followed by UTI
What causes chorioamnionitis?
Low pathogenic commensalism anaerobic vaginal or bowel bacteria
Bacterial vaginosis
GBS (rarely in SA)
How does chorioamnionitis affect the mother and the etus?
The mother is usually asymptomatic
Infection causes inflammation in the baby, affecting the prostaglandin pathway, leading to preterm labour
What are complications of chorioamnionitis in the mother?
PPROM
Preterm labour
Endometritis
Septicaemia
What are the complications of chorioamnionitis in the baby?
Congenital bacterial infection (due to colonization at birth or acute chorioamnionitis) Early onset (7/7) meningitis
How is chorioamnionitis managed in mother and/or baby?
IVI ampicillin - crosses placenta
+/- gentamicin/ metronidazole (if septicaemic)
What is the most common cause of puerpural sepsis?
GBS
What is the indication if the baby is sick and proved to have GBS?
The mother is a carrier and needs prophylactic antibiotics in the next pregnancy
When are antibiotics effective in women with preterm labour?
PPROM
Mother ill- maternal fever in labour, clinical signs of bacterial infection
What is chlamydial infection associated with in the newborn?
Eye infection
Pneumonia
What is gonorrhoeal infection associated with in the newborn?
Eye infection
Regarding TB, what type is problematic and what is the management plan?
Cavitatory TB is the problem
Treat mother - no longer infectious after 2/52
Give baby INH prophylaxis if mother
How does primary symptomatic syphilis present?
Chancre
Painless regional lymphadenopathy
How does secondary syphilis present?
Rash (palms and soles) Also pedis Snail track ulcers Generalized adenopathy Malaise
Is latent syphilis still infectious to the fetus?
Yes
What tests are used in primary syphilis screening?
VDRL
RPR
Strip test
What tests are used in secondary syphilis screening?
FTA
TPHA
What are the benefits of RPR?
Very cheap
Expressed as positive or negative
Rapid test available
Can be performed on CSF
How is VDRL performed?
In lab.
Expressed as titre- rx if >1/16. If
What are the benefits of the strip test?
Cheap
High sensitivity and specificity
Result in 5-20 min
How is primary syphilis managed?
Benzathine benzyl penicillin 2.4mU IMI x 3 doses 1/week
How is secondary or early latent syphilis managed?
Benzathine benzyl penicillin 2.4mU IMI x 3 (weekly)
How is syphilis treated if penicillin allergy? What is the problem with this?
Doxycycline or erythromycin - may not protect fetus
What are the signs of congenital syphilis?
LBW, Preterm, UGA HSM + Jaundice + Purpura + Anaemia Blisters on palms and soles (contagious) + Peeling skin Oedema Osteitis Pneumonia alba
What is the neonatal rx of congenital syphilis?
If symptomatic or XR involvement: procaine penicillin 50000iU/kg for 19 days
(Congenital syphilis is equivalent to secondary in adults)
When do you treat an asymptomatic baby for syphilis?
Mother asymptomatic but treated (latent)
Partially treated
Rx completed within last 4/52 pregnancy
Treated with erythromycin
What do you use to treat an asymptomatic baby exposed to syphilis in utero?
Benzathine penicillin 50000iU/kg IMI stat
Equivalent to latent phase in adults therefore stat dose
What are the TORCHES infections?
Toxo
Rubella
CMV
Herpes
When does an infant contract congenital hep B and from what?
Contracted at delivery or after birth from blood or vaginal secretions
When, according to national protocol, is an infant vaccinated against hep B?
At 1/12
Which two clinical scenarios result in a different hep B vaccination protocol for the infant?
Mother known carrier
Acute hepatitis during pregnancy
What is the management for an infant of a known hep B carrier or of mother with acute hep in pregnancy?
Baby gets extra vaccine at birth and hep B IgG if available
What is seen on histology in a CMV infection?
Infected cells are swollen
Multinucleate giant cells
What are the complications seen in the infant with congenital CMV infection?
Seizures, mental retardation, microcephaly Micropthalmia, Chorioretinitis HSM, Blueberry muffin rash Late onset neural deafness Pneumonitis
How does rubella present?
Fever and flu-like symptoms
Red maculopapular rash, face to extremities
Lymphadenopathy, posterior auricular and suboccipital
‘3/7 day measles’ but not as severe (no encephalitis)
Self-limiting arthritis in young women
How is rubella diagnosed antenatally?
Antenatal USS
Amniotic fluid culture
What complications follow T1 rubella infection?
Malformations - cardiac
What are the complications of rubella in pregnancy?
Seizures, mental retardation, microcephaly
Deafness
Micropthalmia, chorioretinitis, cataracts
HSM, blueberry muffin rash
What are the signs of congenital toxoplasmosis?
Seizures, mental retardation, microcephaly
Encephalitis, peri ventricular hydrocephaly, intracranial calcification
Deafness
Micropthalmia, chorioretinitis
When is the baby at increased risk of getting herpes?
If the mother has active herpes at delivery
If mother’s first infection is during pregnancy (no antibodies to cross placenta)
How does the infant contract herpes?
Through exposure to infected maternal secretions at delivery or if prolonged ROM
What is heroes treated with?
Acyclovir
What duration of treatment is required before the baby is safe from herpes infection at delivery?
48 hours rx
How does HIV affect the pathogenesis of herpes virus?
More viral replication and shedding
Up until when does viral shedding occur?
Up to 6/52 after infection
How is herpes diagnosis confirmed?
PCR, culture, serology
How does herpes infection present in the newborn?
Local involvement of mouth, skin or eyes
Encephalitis
Disseminated herpes infection
What signs on USS should raise suspicion regarding congenital infection?
Symmetrical IUGR Big placenta Hydrops fetalis Big liver or spleen Brain calcifications
What signs raise suspicion about congenital infections in a newborn?
SGA baby
Flat, unwell, poor feeding
Mother RPR positive and untreated, or unknown- always check
Heavy placenta (>1/7 baby’s weight)
Any specific signs or symptoms of individual infections
What infections are of perinatal relevance?
Bacterial- UTI, chorioamnionitis, TB, gonorrhoea/chlamydia, syphilis
Viral - Hep B, CMV, rubella, herpes
Other- toxo
