Neonates: Congenital Infections & SIDS

Question 1

What is rubella (German measles)?

Answer 1

A viral infection.

Question 2

If rubella is contracted during pregnancy, what is there a risk of?

Answer 2

Congenital rubella syndrome

Question 3

When is the risk of congenital rubella highest?

Answer 3

The risk is highest during the first 3 months of pregnancy.

Question 4

Why is rubella now very rare (<5 cases a year in the UK)?

Answer 4

Due to MMR vaccine

Question 5

How can women planning to become pregnant reduce their risk of rubella infection?

Answer 5

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

Question 6

Can pregnant women receive the MMR vaccine?

Answer 6

No - it is a live vaccine.

Non-immune women should be offered the vaccine after giving birth.

Question 7

What are the clinical features of rubella infection?

Answer 7

• 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

Question 8

What is a maculopapular rash?

Answer 8

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.

Question 9

What are the features of congenital rubella syndrome?

Answer 9

1) Congenital cataracts

2) Congenital heart disease (PDA and pulmonary stenosis)

3) Learning disability

4) Hearing loss

Question 10

Pregnant women can be tested for rubella infection and immunity.

What 2 tests are performed?

Answer 10

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.

Question 11

Incubation period of rubella?

Answer 11

14-21 days

Question 12

Management of a pregnant woman with a positive rubella screen?

Answer 12

Refer to foetal medicine specialist.

Maternal –> no treatment, self-limiting (inform her that she is infective)

Question 13

What affects the risk of vertical transmission, and likelihood of developing congenital rubella syndrome?

Answer 13

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).

Question 14

Risk of Congenital Rubella Syndrome if infection at <12 weeks gestation?

Answer 14

90%, with high likelihood of multiple defects.

It is reasonable to consider a termination of the pregnancy.

Question 15

Risk of Congenital Rubella Syndrome if infection at 12-16 weeks gestation?

Answer 15

20%m with single defects most common.

Can do prenatal diagnosis of foetal rubella infection.

Question 16

Risk of Congenital Rubella Syndrome if infection at >20 weeks gestation?

Answer 16

No additional risk.

Question 17

The clinical features of congenital rubella syndrone can be classified into ‘present at birth’ and ‘late onset’.

What are some ‘present at birth’?

Answer 17

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

Question 18

What are some ‘late onset’ features of congenital rubella syndrome??

Answer 18

1) diabetes mellitus

2) thyroiditis

3) GH abnormalities

4) behavioural disorders

Question 19

What is the varicella zoster virus (VZV) responsible for?

Answer 19

1) Chickenpox - a result of primary infection.

2) Shingles (herpes zoster) - a result of viral reactivation.

Question 20

Is VZV dangerous to contract during pregnancy?

Answer 20

Yes - if contracted during pregnancy there is increased morbidity and mortality for both mother and fetus.

Question 21

Clinical features of primary maternal VZV infection?

Answer 21

• pruritic maculopapular rash: characteristically becomes vesicular and crusts before healing
• can be associated with pneumonia, hepatitis, and encephalitis in mothers

Question 22

What can severe cases of VZV infection in pregnant women lead to?

Answer 22

Varicella pneumonitis, hepatitis or encephalitis in mothers.

Question 23

What can be done to determine the immunity status of a woman against VZV?

Answer 23

IgM and IgG antibodies to varicella zoster.

Question 24

What are the management steps in a case where a pregnant woman has encountered a person infectious with VZV?

Answer 24

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.

Question 25

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?

Answer 25

They should receive varicella zoster immunoglobulin (VZIG) within 10 days of the contact, and before the onset of rash.

Question 26

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?

Answer 26

The woman can receive either VZIG, or alternatively Aciclovir can be given from days 7 to 14 following exposure

Question 27

If VZV infection is confirmed in pregnant woman, what is next step?

Answer 27

If >20 weeks gestation –> Aciclovir (800mg PO 5tds) in patients presenting within 24 hours of rash onset.

Consider aciclovir prescription in mothers <20 weeks.

Question 28

What are the 2 potential foetal complications of maternal VZV infection?

Answer 28

1) Varicella of the newborn

2) Foetal varicella syndrome

Question 29

What is the key risk factor for varicella of the newborn?

Answer 29

If maternal chickenpox occurs within the last 4 weeks of the pregnancy.

This confers a 50% risk of varicella infection of the newborn.

Question 30

Possible routes of infection in varicella of the newborn?

Answer 30

1) transplacental

2) vaginal

3) direct contact after birth

Question 31

Management of varicella of the newborn?

Answer 31

Varicella-zoster immunoglobulin (VZIG) +/- aciclovir.

Question 32

What is foetal varicella syndrome caused by?

Answer 32

Subsequent reactivation of of the virus in utero as herpes zoster.

This reactivation ONLY occurs when the fetus is infected by maternal varicella before 20 weeks gestation.

Question 33

Clinical features of foetal varicella syndrome?

Answer 33

1) Skin scarring in a dermatomal distribution

2) Eye defects:
- Microphthalmia
- Choriorenitis
- Cataracts
- Optic atrophy

3) Hypoplasia of the limbs

4) Neurological abnormalities:
- Microcephaly
- Cortical and spinal cord atrophy
- Seizures
- Horner’s syndrome

Question 34

If a mother with suspected contact with infectious VZV person is found not to have immunity and is <20 weeks gestation, how soon should IV varicella immunoglobulins be given?

Answer 34

Within 10 days of exposure

Question 35

What are 5 key maternal infections that can have foetal complications?

Answer 35

1) Rubella

2) Varicella zoster virus

3) Cytomegalovirus

4) Toxoplasmosis

5) Zika virus

Question 36

What is the most common virus transmitted to the fetus during pregnancy?

Answer 36

Cytomegalovirus

Question 37

What % of maternal CMV infections are then vertically transmitted to the fetus?

Answer 37

1/3

However, only 5% of fetal infections will cause CMV related damage to the fetus, with the risk highest in the first trimester.

Question 38

In what trimsester is the risk of CMV related damage to the fetus highest?

Answer 38

1st trimester

Question 39

Clinical features of maternal CMV infection?

Answer 39

Usually asymptomatic.

It can occasionally produce a mild flu-like illness.

In some patients, it can cause a mononucleosis syndrome (similar to Epstein-Barr); resulting in fever, splenomegaly and impaired liver function.

Question 40

If maternal cytomegalovirus infection is suspected, what is next investigation?

Answer 40

Viral serology for CMV specific IgM and IgG

Question 41

Management of maternal CMV infection in an immunocompetent woman?

Answer 41

No treatment.

Question 42

How can foetal CMV be diagnosed prenatally?

Answer 42

Via amniocentesis and PCR of the resulting amniotic sample.

Question 43

When must amniocentesis to diagnose foetal CMV infection be carried out?

Answer 43

After 21 weeks gestation, because functioning fetal kidneys are required for the virus to be excreted into the amniotic fluid.

Question 44

Management of confirmed foetal CMV infection?

Answer 44

There is no effective therapy.

Termination of pregnancy can be offered.

If the woman wishes to continue the pregnancy, serial ultrasound scanning should be performed to assess for manifestations of congenital CMV.

Question 45

Clinical features of congenital CMV?

Answer 45

1) Intrauterine growth restriction

2) Hepatosplenomegaly

3) Thrombocytopaenic purpura

4) Jaundice

5) Microencephaly

6) Chorioretinitis

There is 20-30% mortality in this symptomatic group. This is often due to disseminated intravascular coagulation (DIC), hepatic dysfunction and/or bacterial superinfection.

Babies born without symptoms of CMV infection have a 10-15% chance of developing sequelae of the infection within 2 years. This may include:

1) Sensorineural hearing loss
2) Psychomotor development delay
3) Visual impairment

Question 46

How is the zika virus spread?

Answer 46

• By the Aedes mosquito
• It can also be spread by sex with someone infected with the virus.

Question 47

Presentation of zika virus infection in adults?

Answer 47

Typically asymptomatic, or causes minimal symptoms or a mild flu like illness.

Question 48

What can zika virus infection in pregnancy result in?

Answer 48

Congenital zika syndrome

Question 49

What are the features of congenital zika syndrome?

Answer 49

1) microcephaly

2) foetal growth restriction

3) intracranial abnormalities e.g. ventriculomegaly and cerebellar atrophy

Question 50

Management of pregnant women that may have contracted the Zika virus?

Answer 50

1) Test for the viral PCR and antibodies to the Zika virus

2) Positive result –> refer to fetal medicine to monitor the pregnancy (there is no treatment for virus)

Question 51

What is toxoplasmosis?

Answer 51

Infection with the Toxoplasma gondii parasite via the GI tract, lung or broken skin.

Question 52

Transmission of Toxoplasma gondii?

Answer 52

The usual animal reservoir is the cat, although other animals such as rats carry the disease.

It is primarily spread by contamination with faeces from a cat that is a host of the parasite.

Question 53

Presentation of toxoplasmosis infection in immunocompetent?

Answer 53

Usually asymptomatic.

Symptomatic patients usually have a self-limiting infection, often having clinical features resembling infectious mononucleosis (fever, malaise, lymphadenopathy).

Other less common manifestations include meningoencephalitis and myocarditis.

Question 54

Investigation of choice in suspected toxoplasmosis?

Answer 54

Serology

Question 55

Impact of toxoplasmosis infection in HIV/immunosuppressed patients?

Answer 55

Cerebral toxoplasmosis accounts for around 50% of cerebral lesions in patients with HIV:

Constitutional symptoms, headache, confusion, drowsiness.

Question 56

What can toxoplasmosis infection in pregnancy cause?

Answer 56

Congenital toxoplasmosis

Question 57

When is the risk of congenital toxoplasmosis higher in pregnancy?

Answer 57

The risk is higher LATER in pregnancy

Question 58

What triad of features is seen in congenital toxoplasmosis?

Answer 58

1) Intracranial calcification

2) Hydrocephalus

3) Chorioretinitis (a type of uveitis involving the posterior segment of the eye, which includes inflammation of the choroid and the retina of the eye)

Question 59

What is the commonest cause of death in the first year of life?

Answer 59

Sudden infant death syndrome (‘cot death’)

Question 60

When is sudden infant death syndrome (SIDS) most common?

Answer 60

At 3 months of age

Question 61

What is SIDS?

Answer 61

Sudden infant death syndrome (SIDS) is a sudden unexplained death in an infant.

Question 62

What are the major risk factors for SIDS?

Answer 62

1) Prematurity (4x)

2) Hyperthermia (e.g. over-wrapping) or head covering (e.g. blanket accidentally moves)

3) Bed sharing

4) Parental smoking

5) Putting the baby to sleep prone

Question 63

Protective factors for SIDS?

Answer 63

1) Breastfeeding

2) Room sharing (but NOT bed sharing)

3) Use of dummies (pacifiers)

Question 64

What are some measures that can reduce the risk of SIDS?

Answer 64

1) Put the baby on their back when not directly supervised

2) Keep their head uncovered

3) Place their feet at the foot of the bed to prevent them sliding down and under the blanket

4) Keep the cot clear of lots of toys and blankets

5) Maintain a comfortable room temperature (16 – 20 ºC)

6) Avoid smoking. Avoid handling the baby after smoking (smoke stays on clothes).

7) Avoid co-sleeping, particularly on a sofa or chair

8) If co-sleeping avoid alcohol, drugs, smoking, sleeping tablets or deep sleepers

Question 65

What team supports parents with their next infant after a sudden infant death?

Answer 65

Care of Next Infant (CONI)

This provides extra support and home visits, resuscitation training and access to equipment such as movement monitors that alarm if the baby stops breathing for a prolonged period.