How should I approach the management of a pregnant woman who has been exposed to chickenpox?

Management of a pregnant woman exposed to chickenpox:

• Establish the woman's immunity status by testing for varicella-zoster virus immunoglobulin G (VZV IgG) antibodies if results can be obtained within 24–48 hours of exposure. This allows timely referral for antiviral treatment if necessary.
• If the woman has a definite history of chickenpox, shingles, or has received two doses of varicella vaccine and is not immunosuppressed, she can be reassured that she is immune and at low risk of chickenpox.
• If the woman is seronegative (no immunity), urgently seek specialist advice regarding post-exposure prophylaxis, which may include antiviral treatment or human varicella-zoster immunoglobulin (VZIG), especially if oral antivirals are contraindicated.
• All pregnant women exposed to chickenpox from 20 weeks gestation should be offered antiviral post-exposure prophylaxis.
• Advise the woman to promptly seek medical advice if she develops a rash or symptoms suggestive of chickenpox, regardless of prophylaxis or history.
• Close monitoring is essential, with daily review or earlier if deterioration occurs, and a low threshold for hospital admission if severe symptoms or complications develop.

This approach aims to reduce the risk of serious maternal complications and fetal varicella syndrome, which is more likely if infection occurs in the first 28 weeks of pregnancy.