A young woman, approximately 11 weeks pregnant, had gone on an island staycation with her family. Four days prior to their return. her nephew developed a fever, with a vesicular rash appearing one day later. This was subsequently diagnosed to be chickenpox. She had been in close contact with her nephew throughout the staycation. She did not recall ever having chickenpox in her life, and had never been vaccinated. Her husband was concerned after reading up on the internet about chickenpox exposure and pregnancy, and brought her for a medical opinion after the staycation. They had been told that the blood test results for chickenpox antibodies (varicella IgG and IgM) would only be available in 3 days time (it was a weekend), and this is currently the 4th day since her nephew’s fever started.

Question: How should the patient be advised and managed?

[Updated 20 November 2015]

Current guidelines recommend the use of the varicella immunoglobulin (VZIG) in pregnant women who are exposed to chickenpox and have no evidence of immunity to the disease. VZIG is thought to be most efficacious when administered within 96 hours of exposure to the virus. Varicella infection is considered to be highest risk during the first 20 weeks of pregnancy (congenital varicella syndrome).

Given that this patient has no history of chickenpox, has potentially been exposed to chickenpox since 4 days ago, and the varicella serology results will not be available for another 3 days, it would be best if she received VZIG without waiting for the serology results. In practical terms in Singapore, this would mean a trip to NUH or KKH Emergency Departments, as GP’s, polyclinics, and private specialist clinics in Singapore do not routinely stock VZIG, and time is of the essence in this case.