Which of the following sheets or towels should not be placed for a mother preparing for delivery?

In the context of preparing for a mother’s delivery, placing a sheet or towel under the mother’s head is generally not necessary or optimal. The primary focus during delivery is to provide support and absorb fluids while ensuring the patient's comfort. While offering comfort to the head might seem logical, it does not contribute significantly to the delivery process itself.

In contrast, placing a sheet under the buttocks helps to catch any bodily fluids, maintaining a hygienic environment, while placing one under the vaginal opening provides direct support for the delivery and helps manage fluids even more effectively. Additionally, putting a towel over the mother’s abdomen may help in creating a sense of privacy and comfort while also being useful for any immediate post-delivery care.

Therefore, the correct choice is to avoid placing a towel under the mother’s head, as it does not aid in the delivery process in any practical manner and could detract from covering areas that require more focus during this crucial time.