Figure 3 Anatomy of the breast Figure 4 Prolactin Secreted after feed to produce next feed Prolactin in blood Baby suckling Sensory impulses from nipples • More prolactin secreted at night • Suppresses ovulation Works before or during a feed to make the milk flow Figure 5 Oxytocin Oxytocin in blood Baby suckling Sensory impulses from nipples • Makes uterus contract 12 Infant and Young Child Feeding – Model Chapter for textbooks The oxytocin reflex is also sometimes called the “letdown reflex” or the “milk ejection reflex”. Oxytocin is produced more quickly than prolactin. It makes the milk that is already in the breast flow for the current feed, and helps the baby to get the milk easily. Oxytocin starts working when a mother expects a feed as well as when the baby is suckling. The reflex becomes conditioned to the mother’s sensations and feelings, such as touching, smelling or seeing her baby, or hearing her baby cry, or thinking lovingly about him or her. If a mother is in severe pain or emotionally upset, the oxytocin reflex may become inhibited, and her milk may suddenly stop flowing well. If she receives support, is helped to feel comfortable and lets the baby continue to breastfeed, the milk will flow again. Understanding the oxytocin reflex is important in practice, because it explains why it is important to keep a mother and baby together and for them to have skin-to-skin contact, to help the flow of milk. Oxytocin makes a mother’s uterus contract after delivery and helps to reduce bleeding. The contractions can cause severe uterine pain when a baby suckles during the first few days. Signs of an active oxytocin reflex Mothers may notice signs that show that the oxytocin reflex is active: K a tingling sensation in the breast before or during a feed; K milk flowing from her breasts when she thinks of the baby or hears him crying; K milk flowing from the other breast when the baby is suckling; K milk flowing from the breast in streams if suckling is interrupted; K slow deep sucks and swallowing by the baby, which show that milk is flowing into his mouth; K uterine pain or a flow of blood from the uterus; K thirst during a feed. If one or more of these signs are present, the reflex is working. However, if they are not present, it does not mean that the reflex is not active. The signs may not be obvious, and the mother may not be aware of them. Psychological effects of oxytocin Oxytocin also has important psychological effects, and is known to affect mothering behaviour in animals. In humans, oxytocin induces a state of calm, and reduces stress (22). It may enhance feelings of affection between mother and child, and promote bonding. Pleasant forms of touch stimulate the secretion of oxytocin, and also prolactin, and skin-to-skin contact between mother and baby after delivery helps both breastfeeding and emotional bonding (23,24). 2.6 Feedback inhibitor of lactation Milk production is also controlled in the breast by a substance called the feedback inhibitor of lactation, or FIL (a polypeptide), which is present in breast milk (25). Sometimes one breast stops making milk while the other breast continues, for example if a baby suckles only on one side. This is because of the local control of milk production independently within each breast. If milk is not removed, the inhibitor collects and stops the cells from secreting any more, helping to protect the breast from the harmful effects of being too full. If breast milk is removed the inhibitor is also removed, and secretion resumes. If the baby cannot suckle, then milk must be removed by expression. FIL enables the amount of milk produced to be determined by how much the baby takes, and therefore by how much the baby needs. This mechanism is particularly important for ongoing close regulation after lactation is established. At this stage, prolactin is needed to enable milk secretion to take place, but it does not control the amount of milk produced. 2.7 Reflexes in the baby The baby’s reflexes are important for appropriate breastfeeding. The main reflexes are rooting, suckling and swallowing. When something touches a baby’s lips or cheek, the baby turns to find the stimulus, and opens his or her mouth, putting his or her tongue down and forward. This is the rooting reflex and is present from about the 32nd week of pregnancy. When something touches a baby’s palate, he or she starts to suck it. This is the sucking reflex. When the baby’s mouth fills with milk, he or she swallows. This is the swallowing reflex. Preterm infants can grasp the nipple from about 28 weeks gestational age, and they can suckle and remove some milk from about 31 weeks. Coordination of suckling, swallowing and breathing appears between 32 and 35 weeks of pregnancy. Infants can only suckle for a short time at that 13 age, but they can take supplementary feeds by cup. A majority of infants can breastfeed fully at a gestational age of 36 weeks (26). When supporting a mother and baby to initiate and establish exclusive breastfeeding, it is important to know about these reflexes, as their level of maturation will guide whether an infant can breastfeed directly or temporarily requires another feeding method. 2.8 How a baby attaches and suckles at the breast To stimulate the nipple and remove milk from the breast, and to ensure an adequate supply and a good flow of milk, a baby needs to be well attached so that he or she can suckle effectively (27). Difficulties often occur because a baby does not take the breast into his or her mouth properly, and so cannot suckle effectively. K the baby is suckling from the breast, not from the nipple. As the baby suckles, a wave passes along the tongue from front to back, pressing the teat against the hard palate, and pressing milk out of the sinuses into the baby’s mouth from where he or she swallows it. The baby uses suction mainly to stretch out the breast tissue and to hold it in his or her mouth. The oxytocin reflex makes the breast milk flow along the ducts, and the action of the baby’s tongue presses the milk from the ducts into the baby’s mouth. When a baby is well attached his mouth and tongue do not rub or traumatise the skin of the nipple and areola. Suckling is comfortable and often