Obstetrics and Gynecology - A. M. Gromova 2000

Clinical Course and Management of the Postpartum Period
Course of the Postpartum Period
Mammary Gland Function

During Pregnancy, the Mammary Glands undergo changes that prepare them for their future function of milk production. In the postpartum period, The primary function of the mammary glands begins and reaches its peak. During the first 2–3 days after childbirth, the mammary glands produce colostrum—a thick, yellowish, acidic fluid containing protein, fat droplets, epithelial Cells from the alveolar sacs and milk ducts (colostrum corpuscles), as well as salts, CARBOHYDRATES, Vitamins, Enzymes, and Antibodies.

From days 4–5 to 15–18 postpartum, the mammary gland produces "colostral milk," followed by "transitional milk," and only then mature breast milk. Milk is a white fluid that represents a suspension (emulsion) of very fine fat droplets in Blood serum. Milk has an alkaline reaction and does not curdle upon boiling. Its composition includes 87–88% Water, 1.5% protein (albumins, globulins, casein), 3.5–4.5% fats, about 6.5–7% carbohydrates (lactose), and 0.18–0.2% salts. Milk also contains vitamins, enzymes, and antibodies.

Milk secretion is driven by complex reflex and hormonal processes, notably involving prolactin and luteotropic hormone. These Hormones stimulate milk secretion following the prenatal preparation of the mammary parenchyma by estrogens (which develop the milk ducts) and progesterone (which promotes alveolar proliferation). Hormones from the thyroid and Adrenal Glands, acting via the Pituitary Gland, also exert a significant influence. The function of the mammary glands heavily depends on reflex stimuli associated with the act of nursing. On the one hand, this stimulates The production of Pituitary Hormones; on the other hand, triggered by feedback signals from the Central Nervous system, the nipple sphincters relax, facilitating milk ejection.