Which condition may contraindicate the MMR vaccine during pregnancy?

The MMR vaccine, which protects against measles, mumps, and rubella, is a live attenuated vaccine and is generally contraindicated during pregnancy due to the potential for the live virus to affect fetal development. Conditions like multiple myeloma compromise the immune system, leading to a greater risk of uncontrolled viral infection. Patients with multiple myeloma have significant immunocompromised states due to the nature of their illness and treatment, making them more susceptible to infections. Therefore, administering a live vaccine such as MMR in these individuals poses additional safety concerns for both the individual and potential subsequent pregnancies.

In contrast, conditions like asthma, hypertension, and gestational diabetes do not inherently compromise the immune system in a way that is relevant to the administration of the MMR vaccine. While these conditions may require careful management during pregnancy, they do not specifically contraindicate the use of live vaccines unless there are additional complications or specific treatment considerations.