Chickenpox in pregnancy GTG Flashcards
If primary VZV in pregnancy, depending on the gestation when the infection occurs, what can be the impact on the neonate?
- Fetal varicella syndrome (congenital varicella syndrome (CVS) )
- 3-28 weeks - Varicella infection of the newborn (Neonatal varicella)
- Last 4 weeks of pregnancy
What types of virus is VZV?
DNA virus
How is VZV spread?
Highly contagious spread via respiratory droplets and direct personal contact
How does primary infection with VZV present
Fever, malaised, prurutic rash then develop into crops of maculopapules which become vesicular and crust over
What is incubation period of VZV
1-3 weeks
What is the infectious period of VZV
48 hrs before rash until vesicles crust over (normal crust within 5 days)
What % of people who are >15yrs are seropositive for VZV?
90% VZV IgG +ve
How common is primary VZV in pregnancy?
3/1000
Which women are less likely to be seropositive for VZV?
Women from tropical or subtropical countries
If non immune women are be vaccinated before pregnancy, how long should they wait before becoming pregnant?
4 weeks after 2nd dose (2 vaccines 4-8 weeks apart, live vaccine)
Can you be vaccinated if breastfeeding?
Yes
What questions to ask if woman reports contact with chickenpox or shingles?
- Confirm significance of expose
- Type VZV
- Timing of expose
- Closeness of contact (>15 mins same room?) - Previous history of chicken pox
Which women should be offered serological testing?
Uncertain or no history of chicken pox
Women from tropical or subtropical country
80% will have VZV IgG
Perform within 24-48hrs
Who should be offered VZIG?
Not immune and significant contact
For how long after contact is VZIG effective?
10 days
If continuous exposure - 10 days from 1st appearance if rash
If non immune woman has been exposed, how long should they be treated as infectious?
Received VZIG: 8-28 days after expose
No VZIG: 8-21 days after exposure
When should 2nd dose of VZIG be considered?
Further exposure, 3 week or over since last
What % of babies will develop FVS with and without VZIG
Exposure + VZIG: 0%
Without VZIG: 2.8%
What are the signs of fetal varicella syndrome?
Skin scarring
Eye defects
Limb hypoplasia
Neurological abnormality
What serious medical complications can VZV cause in the pregnancy woman
Pneumonia
Hepatitis
Encephalitis
What treatment can be offered to women who develop chickpox rash
PO acyclovir within 24 of rash if > 20 weeks
800mg TDS 7 days
Avoid contact with pregnancy women
If severe chickenpox, what treatment
Admit
IV acyclovir
If possible ideally how long to wait until delivery, if delivery required?
7 days between onset of rash and delivery
Does VZV increase risk of miscarriage
No
FVS can occur if VZV before what gestation, what is the incidence?
28 weeks, 0.9%
When should referral to FMU occur
16-20 weeks
or
5 week after infection
Is amniocentesis helpful in Dx of FVSq
Strong negative predictive value but poor positive in detecting fetal damage
Cannot performa amnio until skin lesions healed
When should infection occur for risk of varicella infection of newborn
Last 4 weeks
What % babies will be infected if primary VZV in last 4 weeks?
50%
Which % of those infected babies will develop clinical varicella?
23%
If born within 7 days of primary VZV what should be given?
VZIG +/- acyclovir
Can women with VZV breastfeed?
Yes
If lesion near nipple - express
Patient leaflets?
RCOG chickenpox in pregnancy
NHS choices risks chickenpox in pregnancy
