Neonates: Congenital Infections & SIDS Flashcards
What is rubella (German measles)?
A viral infection.
If rubella is contracted during pregnancy, what is there a risk of?
Congenital rubella syndrome
When is the risk of congenital rubella highest?
The risk is highest during the first 3 months of pregnancy.
Why is rubella now very rare (<5 cases a year in the UK)?
Due to MMR vaccine
How can women planning to become pregnant reduce their risk of rubella infection?
1) Ensure they have had MMR vaccine
2) If in doubt they can be tested for rubella immunity
3) If they do not have antibodies to rubella they can be vaccinated with 2 doses of the MMR 3 months apart
Can pregnant women receive the MMR vaccine?
No - it is a live vaccine.
Non-immune women should be offered the vaccine after giving birth.
What are the clinical features of rubella infection?
- maternal rubella infection is often asymptomatic
- prodrome e.g. low grade fever, malaise, headache
- diffuse maculopapular rash: initially on the face before spreading to the whole body, usually fades by the 3-5 day
- lymphadenopathy: suboccipital and postauricular
What is a maculopapular rash?
Macule –> A flat, reddened area of skin present in a rash.
Papule –> A raised area of skin in a rash.
The term maculopapular describes a rash with both flat and raised part.
What are the features of congenital rubella syndrome?
1) Congenital cataracts
2) Congenital heart disease (PDA and pulmonary stenosis)
3) Learning disability
4) Hearing loss
Pregnant women can be tested for rubella infection and immunity.
What 2 tests are performed?
IgM antibody –> acute infection
IgG antibody –> present following infection or vaccination
In cases where neither antibody was present, the woman is encouraged to seek rubella vaccination post-delivery.
Incubation period of rubella?
14-21 days
Management of a pregnant woman with a positive rubella screen?
Refer to foetal medicine specialist.
Maternal –> no treatment, self-limiting (inform her that she is infective)
What affects the risk of vertical transmission, and likelihood of developing congenital rubella syndrome?
The gestational age at the time of infection.
Lower gestational age at time of infection = higher risk of congenital rubella syndrome (and higher risk of defects).
Risk of Congenital Rubella Syndrome if infection at <12 weeks gestation?
90%, with high likelihood of multiple defects.
It is reasonable to consider a termination of the pregnancy.
Risk of Congenital Rubella Syndrome if infection at 12-16 weeks gestation?
20%m with single defects most common.
Can do prenatal diagnosis of foetal rubella infection.
Risk of Congenital Rubella Syndrome if infection at >20 weeks gestation?
No additional risk.
The clinical features of congenital rubella syndrone can be classified into ‘present at birth’ and ‘late onset’.
What are some ‘present at birth’?
1) Sensorineural deafness
2) Cardiac Defects:
- Pulmonary Stenosis
- Patent Ductus Arteriosus
- Ventricular Septal Defect
3) Ophthalmic Defects:
- Retinopathy
- Congenital cataracts
4) CNS Abnormalities:
- Learning disabilities
- Microencephaly
5) Haematological:
- Thrombocytopaenia
- Blueberry muffin appearance
What are some ‘late onset’ features of congenital rubella syndrome??
1) diabetes mellitus
2) thyroiditis
3) GH abnormalities
4) behavioural disorders
What is the varicella zoster virus (VZV) responsible for?
1) Chickenpox - a result of primary infection.
2) Shingles (herpes zoster) - a result of viral reactivation.
Is VZV dangerous to contract during pregnancy?
Yes - if contracted during pregnancy there is increased morbidity and mortality for both mother and fetus.
Clinical features of primary maternal VZV infection?
- pruritic maculopapular rash: characteristically becomes vesicular and crusts before healing
- can be associated with pneumonia, hepatitis, and encephalitis in mothers
What can severe cases of VZV infection in pregnant women lead to?
Varicella pneumonitis, hepatitis or encephalitis in mothers.
What can be done to determine the immunity status of a woman against VZV?
IgM and IgG antibodies to varicella zoster.
What are the management steps in a case where a pregnant woman has encountered a person infectious with VZV?
1) Ask if mother has had previous 1ary VZV infection:
If yes –> assume immunity (no further action).
If no –> go to 2)
2) VZV IgG testing required to confirm immunity status.
3) If not immune and <20 weeks gestation –> woman should receive varicella zoster immunoglobulin (VZIG) within 10 days of the contact, and before the onset of rash.
4) If not immune and >20 weeks gestation –> woman can receive either VZIG, or alternatively Aciclovir can be given from days 7 to 14 following exposure.
If a mother with suspected contact with infectious VZV person is found not to have immunity and is <20 weeks gestation, what is next step?
They should receive varicella zoster immunoglobulin (VZIG) within 10 days of the contact, and before the onset of rash.
If a mother with suspected contact with infectious VZV person is found not to have immunity and is >20 weeks gestation, what is next step?
The woman can receive either VZIG, or alternatively Aciclovir can be given from days 7 to 14 following exposure