Pregnancy: Blood borne diseases

Question 1

What is rubella?

Answer 1

• also known as German measles
• a viral infection caused by the togavirus.
• rare since the MMR vacciine

Question 2

If a pregnant woman gets rubella what are the risks?

Answer 2

• spontaenous abortion
• fetal death
• congenital rubella syndrome

Question 3

When during the pregancy is the risk of catching rubella highest in terms of damage to the fetus?

Answer 3

• 8-10 weeks - risk of damage = 90%
• after 16 weeks - rare

Question 4

What are features of congenital rubella syndrome?

Answer 4

• sensorineural deafness
• congenital cataracts
• congenital heart disease (e.g. patent ductus arteriosus)
• growth retardation
• hepatosplenomegaly
• purpuric skin lesions
• ‘salt and pepper’ chorioretinitis
• microphthalmia
• cerebral palsy

Question 4

What are RF for contracting rubella?

Answer 4

incomplete immunisation, exposure to infectious contacts, and international travel

Question 5

How might a woman with rubella present?

Answer 5

• maculopapular rash (begins on face and spreads to head and feet lasts 3-4 days)
• fever
• arthralgias ( 70% adult women fingers wrists knees)
• lymphadenopathy
• pt with unsure immunisation

Question 6

Investigations for rubella?

1

Answer 6

1. Serology - rubella specific IgM serum antibody.
   * Result : IgM raised in acute serum (recently exposed). this is confirmed by later IgG with 4 fold rise in 2-3 weeks)
2. FBC - can cause thrombocytopenia

NOTE:
* v similiar clinically to parovirus B19 so check parovirus B12 serology as 30% risk of transplacental infection, with a 5-10% risk of fetal loss

Question 7

You suspect a pregnant woman has rubella. Who do you need to inform?

Answer 7

suspected cases should be discussed immediately with the local Health Protection Unit (HPU)

Question 8

How do you manage rubella in pregnancy?

Answer 8

• discuss with local Health Protection Unit
• rubella no longer checked at booking visit so if tested and not immune tell to avoid anyone who might have it
• offer MMR vaccination in post natal period (should not be given to pregnant / trying to get pregnant)

BMJ BP
* refer to high risk perinatal specialist and paediatric infectious disease specialst to evaluate risk of fetal infection
* termination an option if high risk of congenital ruubella syndrome
* high dose intramuscular immunoglobulin is not proven to prevent congenital rubella syndrome so not routinely recommended (might use if woman would not consider termination)

Question 9

What is the incubation period for rubella in pregnancy?

Answer 9

• Incubation period i= 14-21 days
• People are infectious from 7 days before they get symptoms and up to 4 days after the onset of the rash.

Question 10

What is cytomegalovirus (CMV?)

Answer 10

• Herpes virus
• Very common over 50% have been exposed to it
• primary infection for people with normal immune system is usually asymptomatic.
• after primary infection CMV establishes life long latency in host cells
• periodic re-activations controllled by immune system
• Problem for immunocompromised

Question 11

What are the features of congenital CMV infection in the newborn?

Answer 11

• growth retardation
• pinpoint petechial ‘blueberry muffin’ skin lesions
• microcephaly
• sensorineural deafness
• encephalitiis (seizures)
• hepatosplenomegaly

Question 12

Is CMV screened for antenatally?

Answer 12

NO - not routinely

done if mother has:
* mononucleosis-like symptoms such as lymphadenopathy, rash and sore throat, fatigue, fever

• can be offered to mothers who request testing

Question 13

What investigations would you do for a pregnant woman with CMV?

Answer 13

*Serolgoy - CMV-IgM acute infection, CMV IgG suggests past infection
* Amniocentesis or fetal blood sampling allow for testing of CMV starting from 21 weeks of gestation
* Fetal US every 2-4 weeks after diagnosed CMV to check for abnormalities e.g. growth restriction, microcephaly, enlarged liver

Question 14

treatment for CMV in pregnancy?

Answer 14

No treatment
prevention

Question 15

What is Parvovirus B19?
How is it spread?

Answer 15

A DNA virus- causes erythema infectiosum (fifth disease / slapped cheek syndrome)

Spread by respiratory droplets

Question 16

When is contracting Parvovirus B19 most dangerous for a pregnant mother?

Answer 16

Can effect unborn baby in first 20 weeks of pregnancy

Question 17

What are the symptoms of Parvovirus B19 in pregnant woman?

Answer 17

often no symptoms in pregancy
can get:
* ‘slapped cheeck’ rash
* maculopapular rash
* fever
* arthralgia

Question 18

What is the incubation period for parvovirus B12?

Answer 18

4-20 day incubation period
(50% women in UK are immmune)
people are infectious 3-5 days before appearance of rash

Question 19

If suspect a woman has parvovirus B12, how do you diagnose?

Answer 19

• Maternal IgM and IgG checked. A paired sample in acute and convalecent phase> 10 days apart.
• IgM antibodies appear and IgG titres increase

Question 20

What are the maternal effects of parvovirus B19 ?

Answer 20

minimal unless immunocompromised
* if so, can lead to sudden haemolysis needing blood transfusion to treat

Question 21

What are the fetal consequences of parvovirus B12?

Answer 21

30% fetus’s infected causing
* fetal suppression of erythropoesis
* cardiotoxicity
This leads to:
* cardiac failure
* fetal hydrops

10% of fetus’s infected <20 weeks will die

Question 22

Explain how parvovirus B12 can lead to fetal hydrops

Answer 22

• parvovirus B19 crosses the placenta
• this causes severe anaemia due to viral suppression of fetal erythropoiesis → heart failure secondary to severe anaemia → the accumulation of fluid in fetal serous cavities (e.g. ascites, pleural and pericardial effusions)
• treated with intrauterine blood transfusions

Question 23

How do you manage Parvovirus B12 ?

Answer 23

• No specific treatment
• Serial US looking for signs of fetal anaemia (fetal hydrops and abnormal middle cerebral artery Dopplers)
• if fetus develops anaemia manage in tertiary fetal medicine unit and consider in utero red cell transfusion

Question 24

Contrast chicken pox to shingles

Answer 24

• Chickenpox is caused by primary infection with varicella-zoster virus.
• Shingles is caused by the reactivation of dormant virus in dorsal root ganglion.

Question 25

What are the risks to the fetus of contracting chickenpox in pregnancy?

Answer 25

most important:
Fetal varicella syndrome (FVS)
* about 1% risk if mother infected from 3-28 weeks
* small number <28 weeks and none >20 weeks
* Skin scarring, eye defets (microphthalmia, limb hypoplasia, microcephaly, learning disabilities)

Shingles in infancy
* (1-2% risk if second or thirst trimester)

Severe neonatal varicella
* maternal infection in last 4 weeks of preganncy is a risk. Plan delivery for at least 7 days until after onset of rash to allow antibodies to transfer to child
* if mother gets rash 5 days before to 2 days after birth. this can be fatal to baby in 20% of cases

Question 26

What are the risks of varicella zoster infection in adult woman?

Answer 26

• 5x greater risk of pneumonitis
• pneumonia
• hepatitis
• encephalitis
• Rarely- death

see RCOG green top guidleines for all chickenpox references

Question 27

Can a non-immune woman to varicella zoster be immunised prior to pregnancy?

Answer 27

• antenatal testing is not routine
• if found to be seroneagtive for VZV IgG can be vaccinated prepregnancy or post partum

see RCOG green top guidleines for all chickenpox references

Question 28

If a woman is vaccinated for varicella zoster post pregnancy can she breastfeed?

Answer 28

Yes safe to breastfeed (it is a live virus) but studies have not detected it in the breast milk of vaccinated women

see RCOG green top guidleines for all chickenpox references

Question 29

What is asked about chickenpox antentally? what advice is given?

Answer 29

Booking antenatal visit : ask about previous chickenpox / shingles

if not had or seronegative - advise to avoid contact with chickenpox and shingles. inform healthcare workers of potential exposure without delay

Question 30

If a pregnant woman with no personal history of chicken pox comes to you with significant contact (+15 mins) contact with chickenpox what to do?

Answer 30

• check blood for anitbodies - if none->
• Give VZIG immunoglobulins as soon as possible (effective if given up to 10 days after contact or 10 days from appearance of rash)
• Still treat a pregnant woman as still potentially infections from 8-28 days after exposure if they recieve VZIG

Question 31

If a pregnant woman develops chickenpox (i.e. has rash) how should she be cared for?

Isolation, symptomatic, medical

Answer 31

• isolate from other pregnant woman, neonates, when attending check ups etc until lesions have crusted over (5 days after onset of rash)
• Symptomatic treatment and hygiene to stop secondary bacterial infection

Medical:
* Oral aciclovir if present < 24 hours of onset of rash and are 20+0 weeks of gestation (800mg 5 x dail P0 for 7 days)
* conside aciclovir before 20+0 weeks
* discuss risk and benefits as Aciclovir is not licensed for use in pregnancy.
* IV aciclovir for severe chickenpox.

NOTE: VZIG has no therapeutic benefit once chickenpox has developed and should therefore not be used in pregnant women who have developed a chickenpox rash

Question 32

if a woman develops chickenpox in pregnancy who should she be reffered to?

Answer 32

• fetal medicine specialist - aim to see in varicella infection of fetus can be diagnosed
• at 16-20 weeks gestation or 5 weeks after infection
• for dicussion and detailed US exam

Question 33

What to do if a mother develops chickenpox close to delivery i.e. w/in 4 weeks?

Answer 33

• this means significant risk of infection in newborn
• planned delivery should be avoided for at least 7 days after onset of rah to allow for antibodies to cross from mother to child
• give babies VZIG and treat with aciclovir if develop chicken pox
• neonatalogist should be informed of birth of a woman who develops chickenpox at any stage

Question 34

Give features a baby might be born with if the mother contracted:

Rubella
Toxoplasmosis
CMV

Answer 34