Generally half an hour after delivery, you can open the milk, milk by the body lactin, fetal sucking action will stimulate lactin secretion, so half an hour after delivery, you can let the baby suck on the nipple, promote milk secretion. After delivery, the body’s estrogen and progesterone levels drop rapidly, inhibiting the release of prolactin inhibitory factor, under the action of prolactin, the mammary udder gland cells begin to secrete milk. Every time the baby sucks water to stimulate the nipple, prolactin is released in a pulsatile manner, promoting milk secretion. If the mother’s body is in good condition after delivery, she can let the baby suck on the nipple after half an hour. Milk contains a lot of antibodies and rich in fat and protein in the week after delivery, which helps newborns grow and develop and resist disease erosion, so you should give your baby more sucking on the nipple.