Introduction:
From conception, the body prepares itself to welcome the baby. During pregnancy, the breasts enlarge, and various hormones are secreted to produce milk. Breast milk contains nutrients and immune cells, which help the child to grow and protect the baby from various infections.
What Is a Breast Tissue Made up Of?
The breasts are a pair of organs seen in every mammalian creature. The breast tissue is made up of soft tissues, ducts for milk secretion, muscles, numerous sac-like structures known as lactiferous ducts, which eject the milk out, the dark-colored area around the nipples known as areola which provides an identification mark for the baby to suck milk, fat tissues, ligaments, and various blood vessels which together help the breasts to produce milk. Various neural pathways are also involved in the process of lactation. When the baby starts to breastfeed, the mechanoreceptors in the nipple get activated and send signals to the brain. These signals alert the hypothalamus in the posterior pituitary gland to release oxytocin hormone. The cry of the baby can also send stimulus to the brain and helps in producing milk.
What Are the Changes Observed in Breasts During Pregnancy and Post Delivery?
The body undergoes several changes during pregnancy and post-delivery. The body is said to be in a puerperium stage, where it regains its non-pregnant state within six weeks after the delivery. The various processes involved are as follows:
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Mammogenesis: After the egg is fertilized in the female uterus, the body starts producing hormones that change the breast tissues, increasing their size. During mammogenesis, the development of breasts occurs.
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Lactogenesis: Breast milk is produced by lactogenesis in one and two stages. During these stages, milk is made and ejected from the mammary ducts.
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Galactokinesis: In this stage, the milk is expelled through a cluster of sacs known as breast alveolus, in which milk is stored.
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Galactopoiesis: During this time, breast milk is preserved or maintained for further milk production.
What Are the Differences Observed in the Quantity and Quality of Milk With Each Passing Day After Delivery?
The composition and quality of breast milk change over the consecutive days after delivery. Breast milk occurs in three stages. They are:
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Colostrum: Post-delivery, the very first milk ejaculated from the mother's breast is thin and yellow. This is called colostrum. It helps to build the child's innate immunity and helps develop gut flora for digestion.
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Mature Milk: After three to four days of delivery, the colostrum milk slowly changes into thin watery milk. This is also known as transitional milk.
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Creamy Milk: Gradually, the milk gains thicker consistency and is tastier and sweeter. This milk is rich in protein, carbohydrates, sugar, minerals, and immunity to the infant.
A healthy mother produces around 500 to 800 milliliters of milk a day. This requires an intake of 700 kilocalories per day. For the mother to produce milk, she requires five kilograms of fat during pregnancy. This is required to compensate for the nutritional deficiency while lactating.
Which All Hormones Play an Important Role in the Production of Breast Milk?
Various hormones stimulate the production of breast milk. They are:
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Prolactin: Once the mammary gland is completely developed, prolactin is released after delivery. This hormone is responsible for the production of milk from the breasts. It is released from the anterior pituitary gland. Even if the prolactin hormones are secreted in high quantities, it does not induce milk production during pregnancy. This is mainly because of the suppression stimulus created by the progesterone hormone. If the prolactin hormone is not stimulated, it gradually decreases. Increased stimulation of prolactin increases milk secretion. The prolactin gradually falls after every half an hour of breastfeeding.
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Oxytocin: This hormone is a major galactokinase hormone. It helps the contraction of alveoli for the ejaculation of milk through stimulus. This pregnancy hormone also helps in uterine contraction while delivering the baby. It is produced from the posterior pituitary gland. The sucking action of the baby also stimulates oxytocin by creating a stimulus in posterior pituitary gland.
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Galactopoietic Hormone: This hormone maintains the continuous secretion of milk while the baby sucks. It works around 18 to 24 hours a day.
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Feedback Inhibitor of Lactation (FIL): It is locally produced from breast tissue. This is responsible for the inhibition of milk secretion. This protects the breasts from overfilling. After two weeks, regulation of milk from day to day takes place to prevent excess clogging of milk. This is known as supply and demand. The baby slowly learns to suck out all the milk from the breasts.
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Progesterone: This is a pregnancy hormone produced from the placenta. This helps in the development of breast tissue during pregnancy. This converts the normal cells into milk-producing cells known as lactocytes. Beginning from the twelfth week of pregnancy, the breasts produce a yellowish colostrum-like secretion in the lactocytes. These lactocytes are present from the second trimester onwards. This pathway of milk synthesis is known as lactogenesis. After the delivery, progesterone level falls down.
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Estrogen: This hormone is reduced after childbirth and expulses the placenta. The decreased production of estrogen signals both anterior and posterior pituitary glands to secrete prolactin, which is responsible for milk secretion.
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Human Placental Lactogen (HPL): This is produced in the placenta. It is activated during late pregnancy from birth to forty-eight hours. After the child is delivered, there is a greater change in hormonal levels. HPL level falls immediately after childbirth, and estrogen levels decrease by the fifth day.
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Insulin: It supports other hormones during milk synthesis.
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Cortisol: The cortical and insulin hormones help lactocytes in secreting milk. The milk production slowly increases from the first thirty hours until the next forty-eight hours to seventy-two hours. This process is experienced by mothers and is known as ‘milk coming in.’
Conclusion:
All pregnant mothers should be educated on the importance of lactation and various physiological changes to promote this mechanism. Certain post-delivery rituals, like prelacteal feeding the baby with water, honey, and other substances, should be discouraged, and immediate breastfeeding should be practiced. Hormones play a key role in regulating the body’s balance during pregnancy.
