Introduction:
Lactation is the process of forming milk in the mammary glands of the breast. It starts before the birth of the newborn and requires changes in the composition, size, and shape of the breast during developmental stages such as puberty, pregnancy, and lactation. Lactation occurs naturally and under the influence of hormones among pregnant women.
What Is Lactation?
Lactation is a natural process observed among women after giving birth to a baby. This process is due to hormonal changes that occur during pregnancy. Milk is ejected from the breast to feed babies. Even without pregnancy, the lactation process can be initiated by using the same hormones. The lactation process ends once milk formation stops in the mammary glands of the breast.
Normal breasts consist of ducts and lobules, two types of epithelial cells (luminal and myoepithelial cells), and two types of stroma (interlobular and intralobular). Around 6-10 main ducts open onto the surface of the nipple. Large ducts lead to the terminal duct lobular unit. These ducts branch into grape-like clusters of acini to form lobules.
There are three types of lobules: type 1, type 2, and type 3, formed during different stages of a woman’s developmental process. Lobules increase in number and size during pregnancy. By the end of pregnancy, they appear to be separated by stroma. The breasts become mature and functional with the onset of pregnancy.
During puberty, lobules type 1 are formed. More mature structures of lobules called type 2 and type 3 are formed during the menstrual cycle when there is a change in estrogen and progesterone levels. No changes can be observed in breasts once puberty is over until pregnancy.
During pregnancy, alveolar development and epithelium maturation occur due to the rise of progesterone levels. The development of lobule type 3 characterizes early pregnancy due to the influence of chorionic gonadotropin. These lobules are large, and epithelial cells contain acinus.
In late pregnancy, the proliferation of new acini is reduced, and the lumen is distended with a secretory material called colostrum.
Further growth and differentiation can be observed in the lobule with milk secretion during labor and lactation. The breast has an increased glandular component, which will remain throughout lactation.
Involution of the mammary glands may be observed with the cessation of lactation. Breast milk is very good for babies. It provides ideal nutrition, including vitamins, proteins, and fats that can be easily digested. The mother's antibodies help fight viruses and bacteria. Breast milk also provides other anti-infective factors, including immunoglobulin, white blood cells, whey protein, and oligosaccharides. This protects the baby from asthma, allergies, ear infections, respiratory diseases, diarrhea, and the risk of diabetes and obesity.
How Is Milk Produced in Women?
Producing milk in women is known as lactogenesis, and it is divided into three stages. During pregnancy, the volume of breasts increases due to the proliferation of secretory tissues.
Stage 1 Lactogenesis: This stage begins in the 16th week of pregnancy and continues throughout the second half. During this stage, the levels of estrogen and progesterone hormones increase, changing the breasts.
These changes include
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Milk ducts increase, causing the breasts to look and feel fuller.
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Nipples of the breast darken, and the area around the nipple and areolas become larger.
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The Montgomery glands are small bumps on the areola that secrete oil for lubrication of nipples.
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The body begins to form colostrum. Colostrum is a nutritious first milk for the baby. Lactation may start during pregnancy as the body prepares.
Stage 2 Lactogenesis: This stage starts after giving birth to a baby. When the placenta is removed, progesterone levels decrease, raising prolactin, cortisol, and insulin levels. Increased prolactin, cortisol, and insulin levels stimulate the body to produce milk. Prolactin is considered a milk-producing hormone.
Generally, after 2-3 days, milk enters the breast and swells. An increase in milk can be observed, and breasts become tender and full. This is called engorgement of the breasts.
Stage 3 Lactogenesis: This stage is characterized by lactation that occurs among women the rest of the time. In this stage, the removal through breastfeeding is restored. Nipples contain more nerves. When the baby suckles, the body releases prolactin and oxytocin hormones.
Prolactin is responsible for milk production, and oxytocin causes muscle contraction so that the milk passes through the milk ducts. When the baby suckles for 30 seconds, a letdown of the milk occurs; this means milk is being released. During nursing or pumping, the body replaces the amount of milk released.
Is It Possible to Lactate Without Pregnancy?
It is possible to lactate without pregnancy with the help of hormones. This process is complex; medications that mimic the hormones are used for several months to produce milk.
What Are the Factors Affecting Lactation?
Factors that affect lactation include
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When food with poor nutrition is consumed.
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Particular medications.
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There are variations in the levels of hormones.
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Changes to breasts because of either trauma or surgery.
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Presence of history of radiation therapy.
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Certain medical conditions.
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A habit of consuming drugs or alcohol.
What Are the Side Effects of Lactation?
During the process of lactation, the body undergoes many changes that involve hormonal changes. This affects women both physically and mentally. Side effects of lactation include
Engorgement: This condition is characterized by fullness of breasts with tenderness and soreness. It is common in the initial stage of milk production and when women cannot express milk on schedule.
Mastitis: The inflammation of breast tissue is known as mastitis. Mastitis may exhibit pain, swelling, redness, and a change in temperature over the affected area. The main cause of this condition may be blocked milk ducts. This condition may result when there is no complete emptying of the milk from the breasts. It can also occur due to a bacterial infection. This condition can be treated with pain relievers and antibiotics if infection is present. Emptying the milk by feeding or pumping is advised to prevent mastitis.
Dysphoric Milk Ejection Reflex (D-MER): An emotional drop can be seen during the let-down stage of lactation. There may be depression, anxiety, hopelessness, and other negative emotions. This condition may be due to decreased dopamine, a feel-good neurotransmitter.
Conclusion:
Lactation is the process of producing milk to feed newborns. It is very important for mothers and babies, too. Babies are provided good nutrition and help against certain conditions. Mothers benefit from recovering from postpartum, and they are protected against the development of certain cancers. This process brings about hormonal changes in the body. Hence, it is important to know about the lactation process, how the milk is produced, the factors affecting lactation, and the side effects of lactation. It is important to know the process, and any problems can be easily identified and treated effectively. This helps achieve a good quality of life
