INFECTIONS IN PREGNANCY Flashcards
What is the virus responsible for fetal varicella syndrome?
Varicella zoster virus (chickenpox)
What are the features of fetal varicella syndrome?
Skin scarring - 78%
Microcephaly
Eye defects (microphthalmia) - 60%
Limb hypoplasia - 68%
Learning disabilities
At what point in the pregnancy is the fetus at risk of developing fetal varicella syndrome?
1% risk before 20 weeks (often between 8-20 weeks)
Very rare after this
Does not occur after 28 weeks
Apart from fetal varicella syndrome, what are the other risks (to the fetus) of the mother contracting chickenpox whilst pregnant?
Severe neonatal chickenpox
Shingles in infancy
What is the risk of chickenpox to the pregnant mother?
There is a 5 fold increase in the risk of pneumonitis if pregnant with chickenpox vs non-pregnant women
How do we manage a mother who is worried about her exposure to chickenpox?
if doubt about maternal status -> check varicella Ab
If the pregnant women is not immune to varicella + within 96 hours of exposure -> varicella zoster immunoglobulin (VZIG)
If > 96 hours of exposure -> PO valaciclovir (if late pregnancy, lung disease, immunocompromised, smokers or presenting within 24 hours of rash)
vaccine cannot be given
How do you manage a foetus with known exposure to VZV?
1) detailed foetal US at least 5 weeks after infection - repeated until delivery
2) if abnormal US -> amniocentesis for VZV PCR
How do you manage a neonate exposure to maternal chickenpox?
- exposed > 7 days before delivery -> nil intervention
- exposed < 7 days before delivery -> ZIG within 24 hours
- exposed 2-28 days after birth -> ZIG
How do you manage a neonate exposure to chickepox (acquired on their own)?
- if maternal Hx of chickenpox/age appropriate vaccine -> no intervention required
- if uncertain –> check maternal serology –> if negative –> ZIG
- if Sx/preterm –> IV acyclovir
At what point in the pregnancy is the fetus at risk of developing fetal varicella syndrome?
first 8-10 weeks -> 90% risk
rare after 16 weeks
Sx of maternal rubella
ASx in up to 50% mild fever macpap rash arthralgia lymphadenopathy: post-auricular, suboccipital self-limiting
Dx of rubella in mother
paired sample (10-14 days apart)
- appearance of IgM Abs
- > 4x fold increase in IgG
(check parvovirus serology too)
Congenital Rubella Syndrome Sx
sensorineural deafness cardiac: VSD, PDA cataracts hepatosplenomegaly purpuric skin lesions - blueberry muffin microcephaly
Dx of foetal infection
after 20 weeks amniocentesis/cordocentesis;
i. viral PCR/culture
ii. foetal IgM
Px of maternal parvovirus B19
up to 40% is subclinical
rubella-like rash
arthralgia
Foetal effects of parvovirus B19
foetal anaemia & hydrops - 5 weeks after maternal infection
US findings:
ascites, skin oedema, pleural & pericardial effusion, placental oedema
Mx of foetal exposure to maternal infection of Parvovirus B19
nothing to prevent hydrops
monitor w serial US every 1-2 weeks for 12 weeks
Mx of maternal influenza infection
Sx Tx with paracetamol
anti-influenza medication to reduce severity of disease
if infected after birth:
considered non-infectious after 72 hours of Tx w anti-influenza medication - continue breastfeeding but sleep 1m apart
Sx of primary maternal CMV
mononucleosis like syndrome (flu-like)
abnormal LFTs/
rash
What % of neonates develop symptomatic congenital CMV syndrome?
10%
Features of congenital CMV
liver shit - late pregnancy:
- petechiae
- jaundice
- hepatosplenomegaly
- thrombocytopenia
early pregnancy:
- SGA
- microcephaly
- intracranial calcifications
sensorineural hearing loss
chorioretinitis
seizures
Management of Maternal HCV
- maternal HCV serology (note that seroconversion takes 21 days)
- avoid foetal scalp electrodes, scalp blood sampling, vigorous aspiration or oral suction
- encourage breastfeeding
- HBV vaccine within 12 hours of birth
- test baby’s HCV Abs at > 18 months
- test maternal follow up in 6-12 months
What is the risk of Toxoplasmosis transmission to baby?
< 13 weeks: 5-15% -> 60-80% risk of abnormalities
13-24 weeks: 25-40% -> 15-25% risk of abnormalities
24-36 weeks: 30-75%
36 weeks: 72% risk -> 2-10% risk of abnormalities
Px of congenital toxoplasmosis syndrome?
majority are ASx fever macpap rash hepatomegaly microcephaly chorioretinitis seizures jaudnice thrombocytopenia
What are the long term sequelae of untreated congenital toxoplasmosis?
intellectual disability deafness chorioretinitis seizures spasticity
Tx of toxoplasmosis
spiramycin PO syrup for 12 months -> repeat IgG at 6 months
