Chicken Pox in Pregnancy

Question 3

xx

Question 4

Oral PEP

Answer 4

1st line = Aciclovir 800mg QDS
Valaciclovir 1000mg TDS

Give day 7 to day 14 post exposure

Question 5

Aciclovir adverse effects

Answer 5

Headaches, dizziness, nausea, vomiting and diarrhoea

Question 6

Aciclovir in reduced renal funcion

Answer 6

May need to reduce dosing

Question 7

Aciclovir in active IBD

Answer 7

May not be absorbed adequately when there is active inflammatory bowel disease

Question 8

Aciclovir/ valaciclovir licensing

Answer 8

Both drugs are not licensed for PEP for chickenpox or in pregnancy but the evidence for their use in this setting has been considered and recommended by the PHE/UKHSA expert working group

Question 9

When to consider VZIG as PEP

Answer 9

If contraindication or adverse effects to antivirals

If VZV IgG is
(1) negative
(2) < 100 mIU/ml4 in the immunocompetent pregnant woman
(3 < 150 mIU/ml4 in the immunocompromised pregnant woman

Question 10

When to administer VZIG

Answer 10

ASAP or at the very latest within 10 days of the exposure

If continuous household exposures = within 10 days of appearance of the rash in the index case

Question 11

Evidence - administering VZIG

Answer 11

Prevent/ attenuate chickenpox in non-immune individuals
Reduce risk of FVS

Observational study (n= 212 seronegative women) - 50% women developed either a normal or an attenuated form of chickenpox and a further 5% had a subclinical infection

Italian retrospective observational study over 20 years, (1997 to 2016)
VZIG - 42% developed clinical chickenpox
No VZIG - 72% developed chickenpox

Meta-analysis of three case series (2011)
VZIG - 0/142 suffered from FVS
No VZIG -14/498 (2.8%) suffered from FVS

However, a case series chickenpox in <20/40 - 5 women who had been treated with VZIG, one of whom delivered a baby with congenital varicella syndrome

Question 12

Evidence VSIG vs aciclovir

Answer 12

PHE/UKHSA follow up study (2018-2021)

Demonstrated no significant difference in the rate of chickenpox when aciclovir (8/26 [31%]) and VZIG (53/145 [37%]) were used as PEP

VZIG - 10% of women reported pain at injection site, no reported adverse effects in the aciclovir group

Question 13

Further exposure

Answer 13

Repeat VZIG (regardless of whether or not received PEP)

If no seroconversion:
2nd antiviral course prescribed from 7 days after the exposure (for 7 days)
VZIG is used for PEP - repeated if the repeat exposure occurs three weeks or more after the last dose

Question 14

Morbidity/ Mortality in Pregnancy

Answer 14

Pre anti-viral case series - 5% of women developed pneumonia, overall mortality 36%

More recent case series - mortality = 0–14%

Pneumonia may be more severe at later gestational ages due to the effects of the gravid uterus on respiratory function