Final answer:
The best nursing action for a lactating mother with full, warm, taut, tender breasts is to encourage increased breastfeeding frequency to help alleviate engorgement and ensure comfortable lactation.
Step-by-step explanation:
Three days postpartum, when a lactating mother experiences full, warm, taut, tender breasts, the most appropriate nursing action is encouraging increased breastfeeding frequency. This occurs because of the normal physiological changes in the mammary glands which prepare for lactation during the third trimester. With the onset of breastfeeding, the infant's suckling stimulates the hypothalamus to release prolactin from the anterior pituitary, promoting milk production in the mammary glands. Additionally, oxytocin is released, which helps with the ejection of milk.
Lactation involves the synthesis and secretion of milk from the mammary glands in response to the infant sucking at the nipple, providing essential nutrients, including immunoglobulins, to the infant. It's a complex process that is part of a positive feedback loop involving hormonal and mechanical factors. If abruptly interrupted, the mother may experience engorgement and leakage due to the body's preparedness to continue lactation.