The student nurse learns that the hormone necessary for milk production is
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Antipsychotic drugs can increase pituitary prolactin secretion and breast milk production through dopamine antagonism, but the gastrointestinal motility drugs metoclopramide and domperidone are most commonly used off label as galactagogues. Metoclopramide and domperidone block dopamine D2 receptors in the anterior pituitary and, in a limited number of clinical trials, they have had modest efficacy over placebo in initiating and maintaining lactation.2 The best chance for efficacy is if the galactagogue is started within three weeks of delivery.3 Show
The safe duration of galactagogue therapy is controversial. Although increased prolactin can be detected within eight hours of the first dose, about two weeks is required for the breast changes required to sustain milk production. Current recommendations of 10–14 days are based on a limited number of controlled studies and the limited number of longer term controlled clinical trials. MetoclopramideMetoclopramide is a centrally acting drug. It can increase milk supply by 66–100% within 2–5 days in total daily doses of 30–45 mg. While the relative dose in milk ranges from 4.7–14.3%, adverse outcomes in infants have not been reported.4 However:
DomperidoneDomperidone is a peripheral dopamine antagonist. At doses of 10–20 mg three times daily it has comparable efficacy to metoclopramide.4 Little domperidone passes into milk (relative infant dose 0.01–0.04%), so the risk of extrapyramidal effects in the baby is less than with metoclopramide.4 In 2004, the US Food and Drug Administration (FDA) issued an alert that domperidone could cause cardiac arrhythmias. This was in response to its illegal importation into the USA by breastfeeding mothers. The data related to historical cases of high-dose, intravenous use in sick patients receiving cancer chemotherapy. Two case control studies using oral domperidone in a general population supported this rare association. However, only three probable case reports in lactating women have been received by the FDA in postmarketing surveillance.5 Concomitant use of moderate or strong inhibitors of cytochrome P450 3A4 such as ketoconazole can increase plasma concentrations of domperidone and therefore the risk of QT prolongation. In 2013, the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency recommended that the daily oral dose be restricted to a maximum of 30 mg and that domperidone not be used for longer than one week. It is therefore important that women being offered domperidone as a galactagogue have tried non-pharmacological strategies first. They need to be aware of the very low risk of QT prolongation and weigh this against the benefits of breastfeeding. Complementary medicinesHerb-derived galactagogues have been used for centuries in folk medicine to augment lactation. These plants contain lipophilic, pharmacologically active constituents which, if taken in sufficient quantity, can pass into the breast milk. While there are generally few adverse effects (Table), there is limited evidence of efficacy. Most of the supporting evidence is based on case reports, or historical use. Breast milk contains more than just calories and nutrients. In fact, it's chock full of other ingredients, such as hormones. These hormones play a role in a baby's health and development. This is one of the many differences in the makeup of breast milk compared with formula. Many of the hormones in breast milk have only recently been identified, and research is ongoing to determine what specifically these hormones and other components do for babies. It is believed that they offer significant health benefits, as research finds significant health advantages for breastfed babies. Infant formula is, of course, a safe alternative to breast milk—and formula-fed babies also thrive. That said, formula does not contain the same makeup of hormones, antibodies, or enzymes. And, without all the necessary information, it's just not possible to try to recreate the precise hormone composition of breast milk in infant formula. What Are Hormones?Hormones are chemicals that are released into the blood from different parts of the body. They carry messages to organs and tissues to tell them what the body needs and what to do. Hormones can be found in blood, urine, saliva, and breast milk. Hormones have many jobs. They control reproduction, growth and development, metabolism, blood pressure, and other important body functions. What's Inside Your Breast Milk?Breast milk contains many hormones that pass into it from your body. Some hormones are smaller with a simple structure so they can move more easily into breast milk. Other hormones are larger and may not pass into the breast milk well, if at all. The levels of the different hormones in breast milk do not remain constant. In fact, they fluctuate quite a bit, particularly in the postpartum period and once menstruation resumes. So, as time goes on, your breast milk will have more of some hormones and less of others. ProlactinProlactin is the hormone responsible for the production of breast milk. Colostrum, the first breast milk, has high amounts of prolactin. Following the first few days of breastfeeding, the amount of prolactin goes down quickly. After that, the levels of prolactin in breast milk are about the same as the levels of prolactin in the blood. Prolactin and Breastfeeding Thyroid Hormones: TSH, T3, and T4Thyroid hormones are made by the thyroid gland. They perform many important functions, and they affect almost every system in the body. The most important function of the thyroid hormones is to control how the body breaks down food and turns it into energy. This process is called metabolism. Thyroid hormones also regulate breathing, heart rate, digestion, and body temperature. And, they play a vital role in growth and development. Thyroxine (T4) levels in colostrum start out low, but they go up during the first week of breastfeeding. Thyroxine may help the intestines of a newborn develop and mature. During the first few months of life, breastfed babies have much higher levels of thyroxine in their bodies than formula-fed infants do. Small amounts of triiodothyronine (T3) and thyroid-stimulating hormone (TSH) have also been identified in breast milk. It's believed that the thyroid hormones in breast milk help to protect a breastfed newborn from hypothyroidism. However, there isn't enough evidence available to confirm this theory. Epidermal Growth Factor (EGF)The epidermal growth factor stimulates cell growth. It is especially important for the development and maturation of the gastrointestinal (GI) tract, or digestive system, of newborns. EGF can be found in blood, saliva, amniotic fluid, and breast milk. Colostrum contains high amounts of epidermal growth factor. The levels go down quickly after childbirth. But a parent with a very early preemie (between 23 and 27 weeks) will have much higher levels of EGF in their breast milk for the first month after delivery. Having more EGF in early preterm breast milk is important because babies born at this stage have a greater chance of developing GI problems such as necrotizing enterocolitis (NEC). The higher levels of EGF may help to prevent this type of serious intestinal issue. Other growth-promoting factors including human milk growth factors I, II, and III (HMGF), and insulin-like growth factor (IGF-I) have also been identified in human breast milk. Beta-EndorphinsEndorphin hormones are the body's natural painkillers. The beta-endorphins found in breast milk are believed to help newborns deal with the stress of birth and adjust to life outside of the womb. Interestingly, there are higher levels of beta-endorphins in the breast milk of people who have a typical vaginal delivery, those who have a premature baby, and those who do not get an epidural during childbirth. RelaxinRelaxin is a hormone that plays a big role in reproduction. Relaxin, as you may have guessed from the name, relaxes or loosens muscles, joints, and tendons. During childbirth, relaxin in the body works to help soften the cervix and loosen the pelvis to prepare for delivery. It may also have an effect on the growth of the milk-making tissue of the breasts. Relaxin is present in early breast milk, and it continues to be seen in breast milk for weeks after childbirth. The importance of relaxin in breast milk is still unknown, but its function may be related to the newborn's stomach and intestines. Since scientists do not fully understand all that relaxin does, research on this hormone continues. Erythropoietin (EPO)The production of red blood cells in the body is called erythropoiesis. Erythropoietin is a hormone that's made by the kidneys. It tells the body to make more red blood cells. This hormone passes into breast milk and may help to stimulate the production of red blood cells in the newborn. CortisolCortisol is often called the stress hormone. It's a steroid hormone that has many functions in the human body. In colostrum, cortisol is high, but the levels go down quickly and stay at lower levels as breastfeeding continues. Studies show that people who are happy and have a positive breastfeeding experience have less cortisol in their breast milk. The amount of cortisol in breast milk can affect the amount of secretory immunoglobulin A (sIgA). IgA is an important antibody that protects a baby from illness and disease. Higher levels of cortisol are associated with lower levels of sIgA. So, it appears that high levels of stress and cortisol can interfere with the healthy immune-protecting properties of breast milk. The scientific community is not sure exactly what impact cortisol in breast milk has, but they believe that it may:
LeptinThe hormone leptin is made by the body's fat tissue. It controls appetite, weight, and how much energy the body uses. The leptin in breast milk may help to control a baby's weight. Studies show that when breast milk contains more leptin, babies have lower body weight. So, leptin may help to prevent obesity in breastfed babies. Other Hormones Found in Breast MilkOther hormones identified in human breast milk include gonadotropin-releasing hormone (GnRH), insulin, progesterone, estrogen, androgens, gastrin, adiponectin, resistin, and ghrelin. These hormones may also influence the baby's growth and development, but scientists are still exploring how. Which hormone is responsible for milk production quizlet?Prolactin stimulates milk production. Oxytocin causes let-down (push out milk) reflex. Both released by pituitary gland into bloodstream --> reach breast.
What are the roles of prolactin and oxytocin in milk production?The two primary hormones that are needed for lactation are prolactin and oxytocin. Prolactin stimulates milk biosynthesis within the alveolar cells of the breast and oxytocin stimulates contraction of the myoepithelial cells that surround the alveoli, causing the milk to be ejected into the ducts leading to the nipple.
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