Chickenpox in pregnancy GTG

Question 1

If primary VZV in pregnancy, depending on the gestation when the infection occurs, what can be the impact on the neonate?

Answer 1

1. Fetal varicella syndrome (congenital varicella syndrome (CVS) )
   - 3-28 weeks
2. Varicella infection of the newborn (Neonatal varicella)
   - Last 4 weeks of pregnancy

Question 2

What types of virus is VZV?

Answer 2

DNA virus

Question 3

How is VZV spread?

Answer 3

Highly contagious spread via respiratory droplets and direct personal contact

Question 4

How does primary infection with VZV present

Answer 4

Fever, malaised, prurutic rash then develop into crops of maculopapules which become vesicular and crust over

Question 5

What is incubation period of VZV

Answer 5

1-3 weeks

Question 6

What is the infectious period of VZV

Answer 6

48 hrs before rash until vesicles crust over (normal crust within 5 days)

Question 7

What % of people who are >15yrs are seropositive for VZV?

Answer 7

90% VZV IgG +ve

Question 8

How common is primary VZV in pregnancy?

Answer 8

3/1000

Question 9

Which women are less likely to be seropositive for VZV?

Answer 9

Women from tropical or subtropical countries

Question 10

If non immune women are be vaccinated before pregnancy, how long should they wait before becoming pregnant?

Answer 10

4 weeks after 2nd dose (2 vaccines 4-8 weeks apart, live vaccine)

Question 11

Can you be vaccinated if breastfeeding?

Answer 11

Yes

Question 12

What questions to ask if woman reports contact with chickenpox or shingles?

Answer 12

1. Confirm significance of expose
   - Type VZV
   - Timing of expose
   - Closeness of contact (>15 mins same room?)
2. Previous history of chicken pox

Question 13

Which women should be offered serological testing?

Answer 13

Uncertain or no history of chicken pox
Women from tropical or subtropical country

80% will have VZV IgG
Perform within 24-48hrs

Question 14

Who should be offered VZIG?

Answer 14

Not immune and significant contact

Question 15

For how long after contact is VZIG effective?

Answer 15

10 days
If continuous exposure - 10 days from 1st appearance if rash

Question 16

If non immune woman has been exposed, how long should they be treated as infectious?

Answer 16

Received VZIG: 8-28 days after expose
No VZIG: 8-21 days after exposure

Question 17

When should 2nd dose of VZIG be considered?

Answer 17

Further exposure, 3 week or over since last

Question 18

What % of babies will develop FVS with and without VZIG

Answer 18

Exposure + VZIG: 0%
Without VZIG: 2.8%

Question 19

What are the signs of fetal varicella syndrome?

Answer 19

Skin scarring
Eye defects
Limb hypoplasia
Neurological abnormality

Question 20

What serious medical complications can VZV cause in the pregnancy woman

Answer 20

Pneumonia
Hepatitis
Encephalitis

Question 21

What treatment can be offered to women who develop chickpox rash

Answer 21

PO acyclovir within 24 of rash if > 20 weeks
800mg TDS 7 days

Avoid contact with pregnancy women

Question 22

If severe chickenpox, what treatment

Answer 22

Admit
IV acyclovir

Question 23

If possible ideally how long to wait until delivery, if delivery required?

Answer 23

7 days between onset of rash and delivery

Question 24

Does VZV increase risk of miscarriage

Answer 24

No

Question 25

FVS can occur if VZV before what gestation, what is the incidence?

Answer 25

28 weeks, 0.9%

Question 26

When should referral to FMU occur

Answer 26

16-20 weeks
or
5 week after infection

Question 27

Is amniocentesis helpful in Dx of FVSq

Answer 27

Strong negative predictive value but poor positive in detecting fetal damage

Cannot performa amnio until skin lesions healed

Question 28

When should infection occur for risk of varicella infection of newborn

Answer 28

Last 4 weeks

Question 29

What % babies will be infected if primary VZV in last 4 weeks?

Answer 29

50%

Question 30

Which % of those infected babies will develop clinical varicella?

Answer 30

23%

Question 31

If born within 7 days of primary VZV what should be given?

Answer 31

VZIG +/- acyclovir

Question 32

Can women with VZV breastfeed?

Answer 32

Yes
If lesion near nipple - express

Question 33

Patient leaflets?

Answer 33

RCOG chickenpox in pregnancy
NHS choices risks chickenpox in pregnancy