From the Guidelines
Herpes zoster (shingles) poses minimal risk to pregnant women who have had chickenpox or the chickenpox vaccine previously, but can potentially transmit the varicella-zoster virus to non-immune pregnant women, causing chickenpox. The virus that causes shingles cannot be transmitted as shingles itself; rather, a person with active shingles can potentially transmit the varicella-zoster virus to someone who has never had chickenpox, causing chickenpox in that person 1. For pregnant women who have never had chickenpox or the vaccine, avoiding contact with shingles lesions is recommended until they are crusted over. If a pregnant woman without immunity is exposed to someone with shingles, she should contact her healthcare provider promptly as varicella-zoster immune globulin (VZIG) may be recommended within 10 days of exposure, which can reduce the infection rate to 30%, substantially lower than the expected rate of >70% in unimmunized women exposed to varicella 1. This preventive measure helps reduce the risk of developing chickenpox, which could potentially harm the developing fetus. The concern is not about contracting shingles directly, but about a non-immune pregnant woman developing chickenpox, which in rare cases can lead to congenital varicella syndrome in the baby or severe maternal infection. Key considerations for managing exposure include:
- Avoiding contact with shingles lesions until they are crusted over
- Promptly seeking medical attention if exposure occurs
- Considering VZIG administration within 10 days of exposure for non-immune pregnant women
- Understanding that VZIG can reduce, but not eliminate, the risk of chickenpox in non-immune pregnant women 1.
From the Research
Risk of Transmitting Herpes Zoster to Pregnant Women
- The risk of transmitting herpes zoster (shingles) to pregnant women is a concern, as varicella-zoster virus can cause severe or fatal complications in at-risk individuals, including pregnant women 2.
- Pregnant women who are varicella-seronegative and have significant exposure to varicella-zoster virus should be offered zoster immunoglobulin (ZIG) or oral aciclovir prophylaxis to prevent infection or mitigate disease severity 3, 4.
- However, there is a reported case of a pregnant woman contracting primary varicella infection from exposure to close contacts vaccinated with the varicella-zoster vaccine, suggesting that it may not be entirely safe for seronegative gravidas to be in close contact with people vaccinated with the varicella vaccine 5.
- Chickenpox during pregnancy can be life-threatening, particularly if the mother develops complications such as pneumonia, and can also pose a risk to the unborn baby 6.
- Post-exposure management of individuals exposed to varicella-zoster virus, including assessment of immune status and rapid provision of optimal prophylaxis, can help avoid potentially devastating complications of varicella-zoster virus infection 2, 3.