Chickenpox in Pregnancy

Question 1

Can non-immune woman be immunised prior to pregnancy or postnatally?
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Answer 1

• Varicella vaccination prepregnancy or postpartum is an option for seronegative for VZV IgG.
• universal serological antenatal testing not recommended in UK.
• seronegative identified in pregnancy offered postpartum immunisation.
• vaccinated postpartum reassured, safe to breastfeed

Question 2

Can varicella be prevented in the pregnant woman at her initial antenatal visit?

Answer 2

• booking for antenatal care should be asked about previous chickenpox/shingles infection.
• not had chickenpox, or seronegative for chickenpox,
  advised to avoid contact with chickenpox and shingles during pregnancy and to inform healthcare workers of potential exposure without delay.

Question 3

Can varicella infection be prevented in pregnant woman who gives a history of contact with chickenpox or shingles?

Answer 3

• contact: careful history to confirm significance of contact and susceptibility of patient.
• uncertain / no previous history of chickenpox, or who come from tropical or subtropical countries, exposed to infection: blood test to determine VZV immunity or non-immunity.
• not immune to VZV & significant exposure, offer VZIG ASAP. (up to 10 days) after contact (if continuous exposures, 10 days from the appearance of rash in index case).
• Non-immune exposed managed as potentially infectious from 8–28 days after exposure if receive VZIG and from 8–21 days after exposure if not receive VZIG.
• supplies are limited, issues to pregnant may be restricted and clinicians are advised to establish availability of VZIG before offering it to pregnant.
• exposure to chickenpox or shingles (regardless of whether or not received VZIG: asked to notify doctor or midwife early if a rash develops.
• develops rash isolated from other pregnant, when attends GP surgery/hospital for assessment.
• second dose of VZIG if further exposure is reported and 3 weeks have elapsed since last dose.

Question 4

What are the maternal risks of varicella in pregnancy?

Answer 4

increased morbidity with varicella in adults, including 
1 - pneumonia, 
2- hepatitis and 
3 -encephalitis. 
4 - Rarely, it may result in death.

Question 5

How should the pregnant woman who develops chickenpox be cared for?

Answer 5

• develop rash immediately contact GP
• avoid contact with potentially susceptible individuals, e.g. other pregnant and neonates, until the lesions crusted over. This is usually about 5 days after onset of rash.
• Symptomatic treatment and hygiene to prevent secondary bacterial infection of lesions.
• Oral aciclovir prescribed for pregnant with chickenpox if they present within 24 hours of onset of rash and if they are 20+0 weeks of gestation or beyond.
• Use of aciclovir before 20+0 weeks considered.
• Aciclovir not licensed for use in pregnancy and the risks and benefits of its use discussed with woman.
• Intravenous aciclovir given to all pregnant with severe chickenpox.
• VZIG no therapeutic benefit once chickenpox developed and not be used in pregnant who developed rash.

Question 6

Should women be referred to hospital?

Answer 6

• pregnant with chickenpox asked to contact her doctor immediately if develops respiratory symptoms or any other deterioration in her condition.
• Women develop symptoms or signs of severe chickenpox referred immediately to hospital.
• hospital assessment considered in woman at high risk of severe or complicated chickenpox even in absence of concerning symptoms or signs.
• assessment needs to take place in area where not contact with other pregnant.
• Appropriate treatment decided in consultation with a MDT (obstetrician or fetal medicine specialist, virologist and neonatologist.)
• Women hospitalised with varicella should be nursed in isolation from babies, potentially susceptible pregnant women or non-immune staff.

Question 7

When and how should the woman with chickenpox be delivered?

Answer 7

• timing and mode of delivery: must be individualised.

- epidural or spinal anaesthesia: site free of cutaneous lesions should be chosen for needle placement.

Question 8

What are the risks to the fetus of varicella infection in pregnancy and can they be prevented or ameliorated?

Answer 8

• risk of spontaneous miscarriage does not appear to be increased if chickenpox occurs in first trimester.
• If develops varicella or shows serological conversion in first 28 weeks of pregnancy, she has a small risk of fetal varicella syndrome (FVS) and she should be informed of implications.

Question 9

Can varicella infection of the fetus be diagnosed Prenatally?

Answer 9

• develop chickenpox in pregnancy referred to fetal medicine specialist, at 16–20 weeks or 5 weeks after infection, for discussion and detailed US examination.
• amniocentesis strong negative predictive value but poor positive predictive value in detecting fetal damage that cannot be detected by non-invasive methods,: counsell about risks VS benefits of amniocentesis to detect varicella DNA by PCR.
• Amniocentesis should not be performed before skin lesions completely healed.

Question 10

What are the neonatal risks of varicella infection in pregnancy and can they be prevented or ameliorated?

Answer 10

• If maternal infection occurs in the last 4 weeks of a woman’s pregnancy, significant risk of varicella infection of newborn.
• planned delivery avoided at least 7 days after onset of maternal rash to allow for passive transfer of antibodies from mother to child, provided that continuing pregnancy not pose any risks to mother or baby.
• neonatologist informed of birth of all babies born to who chickenpox at any gestation during pregnancy.
• Women with chickenpox should breastfeed if they wish to and are well enough to do so.