A nurse is providing teaching about preventing mastitis to a client who is postpartum and breastfeeding her newborn. Which of the following instructions should the nurse include?

The correct answer is D: Try to have your baby empty your breasts with each feeding. This instruction helps prevent mastitis by ensuring proper milk flow and preventing engorgement. When the breasts are not fully emptied, milk can back up and lead to inflammation and infection. Having the baby empty the breasts also helps maintain milk supply and prevents clogged ducts. In contrast, choices A, B, and C are incorrect because wearing an underwire bra, covering the breasts, and applying cold compresses can all restrict milk flow and potentially lead to mastitis. It's important to promote proper breastfeeding techniques to prevent complications.