Viral infections in pregnancy Flashcards
complications of viruses in pregnancy
Maternal complications (Influenza, VZV, Hep E)
Miscarriage / stillbirth (rubella, measles, Hep E)
Teratogenicity (VZV, Zika)
IUGR / prematurity (rubella / CMV)
Congenital disease (CMV, HSV)
Persistent infection (HIV, Hep B/C)
What viruses do you consider when pregnant woman presents with rash
Varicella Zoster virus (chickenpox/ shingles)
Epstein barr virus
Herpes simplex virus
Cytomegalovirus
Parvovirus B19
Enterovirus
Measles
Rubella
Summarise Herpes viruses
HSV, VZV, CMV, EBV
DNA viruses
once exposed -> lifetime infection
can reactivate under stress/immunosuppression
transmission, incubation and latency of HSV 1 and 2
transmission - close contact
incubation - oropharyngeal/oro-facial 2-12 days; genital - 4-7 days
latency - in nerve cells (dorsal route ganglia) - linked to nerve cells
Sx of HSV 1 and 2
asx
painful vesicular rash
lymphadenopathy
fever
Diagnosis of HSV1 and 2
Viral detection -lesion swab for PCR
serology - if immunocompromised
IgG develops in 1st 12 wks
seroprevalence is 20-60%
Summarise HSV transmission in pregnancy
foetal infection - active infection in genital, have PPROM so that infection can ascend. If have instrumental/PPROM might increase risk
neonatal infection
* direct contact with maternal secretions in delivery
* oral herpes - kissing baby
* non familial transmission
different stages of HSV infection in pregnancy
Primary infection = first occurrence of gential HSV. No pre-existing HSV1 or HSV2 antibodies.
Non-primary infection: 1st episode of gential HSV but only has antibodies to the other type
Recurrent: HSV is the same as pre-existing antibodies. Infection may prev have been asymptomatic or symptomatic.
Consequence of HSV infection in pregnancy
Vertical transmission
* risk in 3rd trimester with primary genital infection
* if active HSV in final 3wks before delivery - then CS required
* if have regular recurrence - have acyclovir suppression in 6wks to due date
In utero infection
* primary infection only
* miscarriage
* congenital abnormalities - ventriculomegaly, CNS abnormalities
* Preterm
* IUGR
Mx of HSV in pregnancy
GUM clinic referral
Acyclovir
HSV anti-body testing, see if exposed before
consider CS 6wks before surgery
if recurrent outbreaks:
* may not treat recurrance
* consider suppressive therapy from 36wks
* Maternal Ab will offer protection - may not prevent transmission
* avoid prolonged ROM/invasive fetal monitoring
Presentation of neonatal HSV
Eye disease – initially may just be excessive watering and conjunctival erythema. Periorbital vesicles may present. HSV keratoconjunctivitis may -> cataracts and chorioretinitis -> permenant visual impairement
Present in lots of ways and easily missed – can just be one lesion.
Disseminated – very unlikely to be able to make a difference
Treatment of neonatal HSV
Acyclovir
Easy to think staph – so do viral swab and treat with acyclovir if worried until get –ve swab
transmission and incubation of VZV
transmission - respiratory (isolate)
70% infection rate if susceptible
infection 7-13 days (mean 14 days)
symptoms of neonatal VZV
Symptoms: prodrome of fever, malaise , myalgia
Centripetal maculopapular rash
Vesicular, appears in crops
Maternal varicella
10-20% of women of childbearing age are susceptible
10-20% of pregnant women with varicella will have varicella pneumonia (v severe)
Encephalitis is rare but mortality is 5-10%
VZV neonatal transmission
antenatal (across the placenta), perinatal or postnatal
0.4% if maternal infection weeks 0-12
2% if weeks12-20
features of congenital varicella syndrome
Neurological – intellectual disability, microcephaly, hydrocephalus, seizures, Horner’s syndrome
Occular abnormalities – optic nerve atrophy, cataracts, chorioretinities, micropthalmost, nystagmus
Limb abnormalities – hypoplasia , atrophy, paresis
GI – GORD, atretic or stenotic bowel
low birth weight
skin scarring
management of maternal exposure to VZV
Post exposure prophylaxis for maternal VZV
oral (or IV if complicated) acyclovir
epidemiology, transmission and incubation of CMV
Common early childhood infection
2-6% of infants infected by 6 months, 40% by 16yrs.
Transmission: salvia/ resp secretions/ urine
Incubation: 4-8 weeks
Virus persists lifelong
Symptoms of CMV
asx
macolopapular rash
infectious mononucleosis-like illness
Ix for CMV
PCR of urine/saliva/amniotic fluid/tissue
serology
CMV in pregnancy
Primary infection in pregnancy – approx. 30% transmit the virus across the placenta
Reactivation or re-infection with a new strain is more common – approx. 1% will transmit infection
Primary – is infection for 1st time ever – in 30-40% of 2nd trimester??
Can get reinfection with a different strain
Biggest risk to baby is transmission in 3rd trimester
Complications from CMV in pregnancy
encephalitis
ventriculomegaly
chorioretinitis
hepatosplenomegaly
thrombocytopenia
jaundice
microcephaly
In older children can -> sensorineural deafness and learning disability.
risk for maternal-fetal viral transmission is lower in early vs late pregnancy,
risk for symptomatic disease at birth and long-term sequelae is higher when infection occurs in early pregnancy.
Most congenitally infected newborns are initially asymptomatic.
15 to 25% initially asymptomatic -> neurodevelopmental abnormalities,eg sensorineural hearing loss, within the first 3yrs
Ventriculomegaly/encephalitis in utero – unlikely to develop normally