en.wikipedia.org/wiki/Breastfeeding#Lactation_without_pregnancy
Breast milk has been shown to be best for feeding a child if the mother does not have any transmissible infections. Nevertheless, some mothers do not breastfeed their children, either for personal or medical reasons.
HTLV-1, which are transmitted through bodily fluids, can be passed through the breast milk, and may therefore preclude breastfeeding in these cases. However, most medicines are transferred in very small amounts and are considered safe to take during breastfeeding. Therefore most women are not precluded from breastfeeding, and doctors and governments are keen to promote the practice. Nevertheless, many medications are labeled as unsafe for use while breastfeeding, and the mother who desires to breastfeed and her physician must carefully weigh the risks and benefits to her baby. Many governmental strategies and international initiatives have promoted breastfeeding as the best method of feeding a child in his or her first year.
Progesterone -- influences the growth in size of alveoli and lobes. Progesterone levels drop along with estrogen levels after birth, triggering the onset of copious milk secretion.
Estrogen -- stimulates the ductule system to grow and become specific. Estrogen levels drop at delivery and remain low for the first several months of breastfeeding.
Oxytocin -- contracts the smooth muscle of the uterus during birth, after birth, and during orgasm. After birth, oxytocin contracts the smooth muscle layer of band-like cells surrounding the alveoli to squeeze the newly-produced milk into the duct system. Oxytocin is necessary for a let-down, or milk ejection reflex, to occur.
Human placental lactogen (HPL) -- HPL is released in large amounts by the placentra during pregnancy (beginning in the second month) that appears to be instrumental in breast, nipple, and areolar growth before birth.
colostrum (a thick, sometimes yellowish fluid), but high levels of progesterone inhibit most milk secretion and keep the volume "turned down". It is considered medically normal for a pregnant woman to leak colostrum before her baby's birth, and also normal not to leak at all. Neither situation is an indicator of future milk production levels in the mother.
birth, the delivery of the placenta results in a sudden drop in progesterone/estrogen/HPL levels. This abrupt withdrawal of progesterone in the presence of high prolactin levels cues Lactogenesis II (copious milk production). Prolactin blood levels rise when the breast is stimulated, and peak around 45 minutes later. The return to pre-breastfeeding levels about three hours afterwards. The release of prolactin triggers the cells in the alveoli to create milk. Some research (Cregan 2002) indicates that prolactin in milk is higher at times of higher milk production, and that the highest levels tend to occur between 2 am and 6 am Other hormones (insulin, thyroxine, cortisol) are also involved, but their roles are not yet well understood. Although biochemical markers indicate that Lactogenesis II commences approximately 30-40 hours after birth, mothers do not typically begin feeling increased breast fullness (the sensation of milk "coming in") until 50-73 hours (2-3 days) after birth.
antibodies than mature milk, and is especially high in immunoglobulin A (IgA), which coats the lining of babies' immature intestines, helping to prevent germs from invading baby's system. Secretory IgA also works to help prevent food allergies.
ISBN 0316779245) After a baby has been nursing for 3-4 days, the colostrum in the breast slowly begins the process of changing into mature breast milk over the next two weeks. After milk supply has been more firmly established, Lactogenesis III begins - the autocrine (or local) control system. At this stage, milk production is made on the law of supply and demand: The more milk removed from the breast, the more milk the breast will produce. Thus milk supply is strongly influenced by how often the baby feeds and well it is able to transfer milk out of the breast. "Low supply" can often be traced to A) too infrequent feeding/pumping, B) a jaw/mouth structure or latch inhibiting baby's ability to transfer milk effectively or C) a metabolic or digestive inability in the infant, rendering it unable to utilize the milk it receives. Research on mothers who express their milk (Hopkinson 1988; deCarvalho 1985) indicate that for most women the more times per day a mother expresses her milk, the more milk she produces. Ongoing research (Daly 1993) shows that more fully draining the breasts also increases the rate of milk production. The production, secretion and ejection of milk is called lactation. Most breastfeeding experts recommend at least one feeding every two to three hours to maintain the milk supply. For most women, a target of eight nursing sessions/pumping sessions per 24 hours seems to keep a milk supply high not only during the early months of lactation, but especially past the fourth month.
nutrient content of mature milk is relatively consistent and draws its ingredients from the mother's food supply and the nutrients in her bloodstream at the time of feeding. If that supply is inadequate, content is obtained from the mother's bodily stores.
carbohydrates compared with the creamier hindmilk which is released as the feed progresses. There is no sharp distinction between foremilk and hindmilk - the change is very gradual. Research from Peter Hartmann's group tells us that fat content of the milk is primarily determined by the emptiness of the breast -- the less milk in the breast, the higher the fat content. The breast can never be truly "emptied" since milk production is continuous.
edit The let-down reflex The let-down reflex, also known as the milk ejection reflex, is caused by the release of the hormone, oxytocin. Oxytocin stimulates the muscles of the breast to squeeze out the milk. Breastfeeding mothers describe the sensation differently, with some feeling a slight tingling, some feeling immense amounts of pressure and slight pain/discomfort, and still others not feeling anything different. The reflex is not always consistent, especially at first. The thought of nursing or the sound of any baby can stimulate the let-down reflex, causing unwanted leakage, or both breasts give out milk when one infant is feeding. However, this and other problems often settle after two weeks of feeding.
oxytocin for triggering milk let-down also causes the uterus to subinvolute (contract down). Subsequently, during breastfeeding mothers can feel uterine contractions (pain ranging from period-like cramps to strong labour-like contractions). Afterpains can be more severe with second and subsequent babies.
edit Benefits The benefits of breastfeeding are both physical and psychological for both mother and child. Nutrients and antibodies are passed to the baby while hormones are released into the mother's system. The bond between baby and mother can also be strengthened during breastfeeding.
edit Benefits for the infant Breastmilk, when fed directly from the breast, is immediately available with no wait and is at body temperature. Breast fed babies have a decreased risk for several infant conditions including Sudden Infant Death Syndrome(SIDS). The sucking technique required of the infant encourages the proper development of both the teeth and other speech organs. The many health benefits of breastfeeding have been well documented. According to the American Academy of Pediatrics policy statement, "Extensive research, especially in recent years, documents diverse and compelling advantages to infants, mothers, families, and society from breastfeeding and the use of human milk for infant feeding. These include health, nutritional, immunologic, developmental, psychological, social, economic, and environmental benefits.
edit Benefits for the mother Breastfeeding also benefits the mother. Breastfeeding releases hormones that have been found to relax the mother and cause her to experience nurturing feelings toward her infant. Breastfeeding as soon as possible after giving birth increases levels of oxytocin which encourages the uterus to contract more quickly. Breastfeeding can als...
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