Final answer:
Breast engorgement on Postpartum day 2-3 is often due to the milk let-down reflex and breasts being overly full as milk production establishes itself. Abrupt cessation of breastfeeding can cause similar symptoms because the body continues to produce milk until hormonal signals reduce lactation.
Step-by-step explanation:
A symptom that can develop on Postpartum day 2-3 when milk let-down occurs and there is breast engorgement is discomfort or pain due to the breasts being overly full with milk. During the lactation process, this engorgement happens as the milk transitions from colostrum to more mature milk, and the supply is still regulating to match the baby's demand. If a woman stops breastfeeding suddenly, her breasts may become engorged with milk, and leakage may occur because her hormone levels haven't yet adjusted to decrease milk production. Engorgement can lead to hardened areas within the breast, and sometimes a fever or flu-like symptoms if not managed correctly.
The let-down reflex, triggered by the infant's suckling and the release of oxytocin, is a crucial component in milk ejection from the alveoli to the ducts and out of the nipple. If lactation is interrupted abruptly, issues such as breast engorgement can occur because the body hasn't been signaled to reduce milk production. It generally takes about a week for the remaining milk to be reabsorbed and production to wind down if breastfeeding is stopped.