Final answer:
A rubella vaccine should not be given to a pregnant woman. The vaccine can be administered after delivery, and the patient should be instructed to use contraception for at least 1 month.
Step-by-step explanation:
A rubella vaccine should not be given to a pregnant woman because the rubella virus is teratogenic, meaning it can cause developmental defects if it crosses the placenta during pregnancy. However, the vaccine can be administered after delivery. Instructing the patient to use contraception for at least 1 month is important to prevent pregnancy during this time and allow the body to recover from childbirth before getting pregnant again.