What is the let-down reflex (milk ejection reflex)?
When you breast-feed, your baby’s suckling stimulates nerves in your nipple. These nerves carry a message to your brain, and the hormone oxytocin is released from your pituitary gland. Oxytocin flows through your bloodstream to your breasts, where it causes tiny muscle cells around your milk glands to squeeze milk out of the glands and into the milk ducts. This is known as the let-down reflex or the milk ejection reflex. Once your let-down is working well (usually by 2 weeks after delivery), you may feel a pins-and-needles or tingling sensation in your breasts when you nurse or pump. Milk will usually drip from one breast while you are feeding on the other side. Sometimes your let-down will occur just when you hear your baby cry or think about nursing your baby. A well-functioning let-down reflex helps ensure your breasts get emptied and your baby easily obtains milk. Sometimes a woman’s milk ejection reflex doesn’t work as well as it should. This can cause breast-feeding difficulties.
