Infections in Pregnancy Flashcards
What causes congenital Rubella syndrome?
- maternal infection with the rubella virus during the first 20 weeks of pregnancy
- risk is highest during the first 10 weeks
How can women planning on becoming pregnant protect against congenital Rubella syndrome?
ensure they have had the MMR vaccine
If someone is unsure whether they have had the MMR vaccine, what is done?
- test for rubella immunity by determining the presence of rubella antibodies
- if these are NOT** present, **2 doses** of the MMR are given, **3 months apart
When should the MMR vaccine be given in pregnancy?
!! pregnant women should NOT receive the MMR vaccine !!
- it is a live vaccine
- non-immune women are offered the vaccine after giving birth
What are the features of congenital rubella syndrome?
- congenital deafness
- congenital cataracts
- congenital heart disease
- pulmonary stenosis
- patent ductus arteriosus
- learning disability
What causes chickenpox?
Varicella zoster virus (VZV)
Why is chickenpox dangerous during pregnancy?
- more severe cases in the mother
- varicella pneumonitis
- varicella encephalitis
- varicella hepatitis
- fetal varicella syndrome
- severe neonatal varicella infection (if infected around delivery)
If in doubt about immunity to VZV, what is done?
- IgG levels for VZV are tested
- if they are positive, this indicates immunity and no risk of infection during pregnancy
- if negative, a vaccination is offered before or after pregnancy
What is the risk to pregnant women who have previously had chickenpox?
- there is NO risk
- if VZV IgG levels are positive, this indicates previous infection
How should women who are not immune to VZV be treated?
IV varicella immunoglobulins
- this is given as prophylaxis against developing chickenpox
- it is given within 10 days of exposure
If a chickenpox rash starts in pregnancy, what can be done?
oral aciclovir
- given if woman presents within 24 hours
AND
- she is more than 20 weeks gestation
When does congenital varicella syndrome occur?
if VZV infection occurs within the first 28 weeks of pregnancy
What are the features of congenital varicella syndrome?
- fetal growth restriction
- microcephaly / hydrocephalus
- learning disability
- scars / skin changes located in specific dermatomes
- limb hypoplasia
- cataracts / chorioretinitis
What is chorioretinitis?
a type of posterior uveitis characterised by inflammation of the choroid and retina
- the choroid contains blood vessels that bring oxygen / nutrients to the eye
- it is between the sclera and the retina
What is listeria and what type of infection does it produce?
- gram-positive bacteria that causes listeriosis
- listeriosis is much more likely in pregnancy
How does listeriosis infection in the mother present?
- may be asymptomatic
- may have a flu-like illness
- rarely can present with pneumonia or meningoencephalitis
What are the complications associated with listeriosis in pregnancy?
- high rate of miscarriage** or **fetal death
- can cause severe neonatal infection
How can listeriosis be avoided in pregnancy?
- listeria is transmitted by unpasteurised dairy products, processed meats + contaminated foods
- women are advised to avoid high-risk foods (e.g. blue cheese)
What causes congenital cytomegalovirus infection?
How is it spread?
- occurs due to CMV infection of the mother during pregnancy
- most cases of CMV do not result in congenital CMV
- it is spread via infected saliva or urine of asymptomatic children
What are the features of congenital CMV?
- fetal growth restriction
- microcephaly
- hearing loss
- vision loss
- learning difficulty
- seizures
How is the Toxoplasma gondii parasite transmitted?
contamination with faeces from a cat that is a host of the parasite
How does Toxoplasma gondii infection present?
What happens when it occurs during pregnancy?
- infection is usually asymptomatic
- it can lead to congenital toxoplasmosis if contracted during pregnancy
- the risk is higher later in the pregnancy
What is the triad of features associated with congenital toxoplasmosis?
- intracranial calcification
- hydrocephalus
- chorioretinitis (cotton-like white/yellow scars on the retina)
What is the triad of features associated with congenital toxoplasmosis?
- intracranial calcification
- hydrocephalus
- chorioretinitis
Who is typically affected by Parvovirus B19 infection?
How does the illness progress?
- typically affects children
- illness is self-limiting with the rash / symptoms resolving within 1-2 weeks
- also called “slapped cheek syndrome”, fifth disease or erythema infectiosum
What are the symptoms associated with Parvovirus B19 infection?
- starts with non-specific viral symptoms
- after 2-5 days, a diffuse bright red rash** appears rapidly across **both cheeks
- a few days later, a reticular mildly erythematous rash** affects the **trunk / limbs
- reticular = “net-like”
- can be raised / itchy
When is someone with Parvovirus B19 infection classed as infectious?
7 - 10 days before the rash appears
- they are NOT infectious once the rash has appeared
What is classed as significant exposure to parvovirus?
- 15 minutes in the same room as someone with parvovirus
OR
- face-to-face contact with someone with parvovirus
What are the complications associated with parvovirus B19 infection in pregnancy?
- miscarriage / fetal death
- severe fetal anaemia
- hydrops fetalis (fetal heart failure)
- maternal pre-eclampsia-like syndrome
!! most likely in the first or second trimester !!
Why does fetal anaemia + heart failure occur in parvovirus B19 infection?
- fetal anaemia is caused by parvovirus infection of the erythroid progenitor cells in the fetal bone marrow / liver
- these make RBCs
- infection causes production of faulty RBCs** that have a **shorter life span
- less RBCs = anaemia
- the anaemia leads to heart failure (hydrops fetalis)
What is maternal pre-eclampsia-like-syndrome and why does it occur?
- also called “mirror syndrome”
- occurs as a result of severe fetal heart failure
- involves a triad of:
- hydrops fetalis
- placental oedema / placetomegaly
- oedema in the mother
- also associated with hypertension + proteinuria
What tests are required in women suspected to have parvovirus B19 infection?
IgM to parvovirus:
- tests for acute infection within the past 4 weeks
IgG to parvovirus:
- tests for long term immunity to the virus after a previous infection
Rubella antibodies:
- as a differential diagnosis
What is the treatment for parvovirus B19 infection during pregnancy?
treatment is supportive
- women are referred to fetal medicine to monitor for complications / malformations
How is the Zika virus spread?
- by the Aedes mosquito in areas of the world where the virus is prevalent
OR
- having sex with an infected individual
What are the symptoms of Zika virus?
- it often causes no symptoms
- can cause a mild flu-like illness
What are the features of congenital Zika syndrome?
- microcephaly
- fetal growth restriction
- intracranial abnormalities
- ventriculomegaly
- cerebellar atrophy
How are women tested to see if they have contracted Zika virus?
What is the treatment?
- tested with viral PCR and antibodies to the Zika virus
- anyone with a positive result is referred to fetal medicine for close monitoring
- there is NO treatment
