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Question 720
Obstetric infection → Viral
Classification
Question
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Assessment of immunity after varicella exposure
Question Stem
A woman at 14 weeks of gestation reports significant exposure to chickenpox. She is uncertain whether she has ever had chickenpox and has never received varicella vaccination. What is the most appropriate next step?
Options
A
Give varicella vaccine immediately
B
Check VZV IgG to determine immunity
C
Give intravenous aciclovir immediately
D
Arrange amniocentesis for VZV PCR
E
No action is required unless a rash develops
Explanation
Following significant exposure, a pregnant woman with an uncertain or absent history of chickenpox should have serological testing to determine VZV immunity. This establishes whether post-exposure prophylaxis is required. Women from tropical or subtropical countries with uncertain immunity should similarly be tested after exposure. Varicella vaccination is not administered during pregnancy.
Option Validity
A) varicella vaccination is not given during pregnancy.
C) intravenous aciclovir is treatment for severe established chickenpox, not the initial assessment of an asymptomatic exposed woman.
D) amniotic-fluid PCR is not used to establish maternal immunity after exposure.
E) susceptibility should be established promptly so that indicated PEP can be offered.
Further Reading
RCOG Green-top Guideline No. 13, Chickenpox in Pregnancy, section 4.3.