Final answer:
The nurse should tell the mother that circumcision is not medically necessary and is a personal choice dependent on factors such as cultural and religious beliefs.
Step-by-step explanation:
When a mother asks whether circumcision is medically indicated for her newborn, the nurse should respond that routine circumcision is a personal choice and not a medical necessity. Circumcision is a surgical procedure to remove the foreskin from the male genitals, which sometimes is performed for religious or social reasons but is not required for all males. The potential health benefits, such as a reduced risk of urinary tract infections, are not sufficient to deem circumcision medically necessary, and the procedure is not without risks. Consequently, the decision to circumcise should be based on parental preference, considering factors like religious beliefs, cultural practices, and personal values.