What is Lactation?
Lactation can be defined as the process of milk secretion from the mammary glands of a female after childbirth. It is the process after which a woman is capable of feeding her milk to her child. The milk produced in the mammary glands of a woman provides nutrition and immunity to the young newborn. At the same time, having milk in the mammary gland is not enough but maintaining it is also important. The stage that maintains milk production and requires prolactin and oxytocin is called Galactopoiesis.
Relation of Pregnancy with Lactation
Lactation is a process that cannot take place in a woman’s body without pregnancy. Therefore, there is a deep association between pregnancy and lactation.
Preparation for Lactation
Generally, a female is ready to produce milk during the fifth or sixth month of her pregnancy. During the latter stages of pregnancy, a female enters the first stage of lactogenesis. At this stage of pregnancy, a woman’s bread makes a thick, yellow fluid known as Colostrum which is extremely nutritious and beneficial for the baby as it is highly rich in immunoglobulin A that boosts the immunity of the newborn. It prevents any pathogens from touching the baby’s body and also prevents food allergies. This fluid is also termed as the first milk of the baby.
Lactation Process
The process by which milk is formed in a woman’s breast is called the Lactation process. This process takes place in the following steps as mentioned below -
The breast starts to grow during the period of pregnancy due to the impact of ovarian hormones and placental hormones. It continues to get larger even after childbirth.
A certain amount of milk is produced in the breast during this period.
There is an increase in milk secretion after the delivery.
The milk is secreted from the mammary gland itself during the process of lactation.
Hormones Responsible for Lactation
Certain hormones that are responsible for the process of Lactation. Let's have a look at them -
The hormones involved in the process of lactation are Estrogen, placental lactogenic, progesterone, prolactin, and oxytocin
This hormone helps in increasing the size of the breast during pregnancy which is caused by the growth of the breast tissue.
A hormone known as the placental lactogenic hormone is higher in our body during pregnancy as this hormone helps in stimulating the growth of the nipple, areola, and breast tissue.
Progesterone is a hormone that helps in increasing the size of the breast tissue along with boosting the milk production in the body. The progesterone hormone level tends to decrease during the post-pregnancy period which helps in stimulating milk production.
A hormone that helps in differentiating the cells that perform their specific functions is called Prolactin
The alveolus is a hormone that is responsible for producing milk after the baby’s birth. This hormone becomes active mainly because of the prolactin hormone. The prolactin hormone is produced once exposed to cortisol hormone.
Once the nipples are regulated, the hormone oxytocin is released causing the alveoli to contract which helps in squeezing the milk out into the duct system. The entire process is called a Let Down However, this process starts only when the nerves of breasts are stimulated.
Things to Avoid During Breastfeeding
It is said that at the time of pregnancy and lactation, what a mother eats or drinks, is automatically being consumed by the baby as well. Therefore, this being the crucial time, a mother needs to look at the things she consumes. Certain things should be avoided during breastfeeding. This includes-
Minimizing of caffeine consumption
Being careful with drugs
Resist the tendency of losing weight by consuming supplements
Alcohol consumption and smoking should be completely stopped
Nutritional Needs During Lactation
Lactation is known as a very crucial time for both the mother and the baby. Therefore, to keep a watch at what we consume is very important. Taking the right amount of nutrients will make the mother and the child healthy. Let’s have a look at the nutrients a woman needs -
Important Nutrients During Lactation
Can Lactation Happen without Pregnancy?
Yes, an artificial lactation can happen without pregnancy. There are three hormones which mainly play a vital role in stimulating the milk that is produced in the mammary glands of a lactating mother. If anyone consumes medicines among these three hormones in the form of supplements, then there are chances that a woman would produce milk in her mammary glands without pregnancy.
At the same time, there are certain other situations where lactation can happen without pregnancy. These include:
Side effects of drugs/medicines.
Health disorders.
Nerve irritation in the breast region.
Overproduction of prolactin hormone in the brain.
Properties of a Lactating milk
After maturation, the milk varies as compared to the milk in an initial stage of lactation. The milk produced at the time of lactation is well established.
Colostrum is the milk that is produced in the initial stage of lactation
The composition of the milk changes gradually after childbirth. Transitional milk is changed from colostrum within four-five days from the childbirth.
A matured milk is produced in mammary glands after 14 to 15 days of childbirth
Slowly, after the demand for milk is reduced by the baby, termination of lactation takes place.
FAQs on Lactation
1. What is lactation and when does it begin in humans?
Lactation is the biological process of producing and secreting milk from the mammary glands to feed a newborn infant. This process is initiated towards the end of pregnancy and becomes fully active after childbirth (parturition). The initial milk produced is called colostrum, which is rich in antibodies and essential nutrients for the baby's first few days.
2. What are the key hormones that regulate the process of lactation?
The regulation of lactation is a complex interplay of several hormones, each with a specific function:
- Prolactin: Secreted by the anterior pituitary gland, this hormone is responsible for stimulating the alveolar cells in the mammary glands to synthesise and produce milk.
- Oxytocin: Released from the posterior pituitary, oxytocin triggers the milk ejection or 'let-down' reflex by causing the contraction of myoepithelial cells surrounding the alveoli.
- Estrogen and Progesterone: During pregnancy, these hormones are crucial for the growth and development of the breast's ductal system and glandular tissue. After childbirth, their levels drop sharply, which allows prolactin to become fully effective.
3. What are the different stages of milk produced during lactation?
Human milk composition changes to meet the evolving needs of the infant. The primary stages are:
- Colostrum: This is the 'first milk' produced for the first 2-4 days after birth. It is a thick, yellowish fluid, low in fat but extremely rich in proteins, vitamins, and antibodies, especially Immunoglobulin A (IgA), which provides crucial passive immunity.
- Transitional Milk: Produced from approximately day 4 to two weeks postpartum, this milk marks the transition from colostrum to mature milk. Its composition gradually changes, with increasing levels of fat and lactose (calories).
- Mature Milk: This is the final milk produced from about two weeks postpartum onwards. It contains a balanced composition of water, fats, carbohydrates (lactose), proteins, and minerals required for the baby's continued growth.
4. What is the 'let-down' reflex and how is it triggered?
The let-down reflex, or milk ejection reflex, is a neuro-hormonal process that makes milk available to the baby. It is triggered by the infant suckling on the nipple, which sends nerve impulses to the mother's hypothalamus. This stimulation causes the posterior pituitary gland to release the hormone oxytocin into the bloodstream. Oxytocin travels to the breasts and causes the tiny muscle cells (myoepithelial cells) around the milk-producing alveoli to contract, squeezing the milk out into the ducts so the baby can drink it.
5. How does lactation provide immunological protection to a newborn baby?
Lactation is a vital mechanism for transferring passive immunity from the mother to the newborn. Breast milk, particularly colostrum, is rich in maternal antibodies, primarily Immunoglobulin A (IgA). When the baby consumes the milk, IgA coats the mucous membranes of the infant's gastrointestinal tract, nose, and throat. This protective layer prevents harmful bacteria and viruses from attaching to the tissues and causing infections, offering crucial protection while the baby's own immune system is still developing.
6. How do the mammary glands prepare for lactation during pregnancy?
During pregnancy, the mammary glands undergo significant changes under hormonal influence. High levels of estrogen stimulate the development and branching of the milk duct system, while progesterone promotes the growth of the glandular tissue and alveoli, where milk will be produced. Although the breasts become capable of producing milk by mid-pregnancy, the high levels of progesterone and estrogen actually inhibit the full secretion of milk. After childbirth, the sharp drop in these hormones allows prolactin to take full effect and initiate copious milk production.
7. Compare the primary roles of prolactin and oxytocin in the process of lactation.
While both hormones are essential for successful breastfeeding, they have distinct and complementary functions. Prolactin is the 'milk-making' hormone; it acts on the alveolar cells within the breast to stimulate the synthesis of milk. In contrast, Oxytocin is the 'milk-releasing' hormone; it triggers the ejection or let-down of milk that has already been produced. In simple terms, prolactin manages the supply, while oxytocin manages the delivery.
8. What is the importance of a mother's diet during the lactation period?
A mother's diet during lactation is crucial for both her own health and the quality of her breast milk. The energy, protein, vitamins, and minerals required for milk production are drawn from the mother's diet and body stores. A well-balanced, nutritious diet ensures that the breast milk contains adequate levels of essential fatty acids (like DHA, important for baby's brain development), vitamins, and minerals. It also helps the mother replenish her nutrient stores and maintain the energy levels needed for childcare and milk production.
9. Is it possible for lactation to occur without a pregnancy? Explain the physiological basis.
Yes, lactation without pregnancy, known as induced lactation or galactorrhea, is physiologically possible. The primary trigger for milk production is the hormone prolactin, which is normally suppressed by high levels of progesterone during pregnancy. Lactation can be induced by mimicking the hormonal changes of childbirth, often through a combination of hormonal therapy and frequent nipple stimulation. This process stimulates the pituitary gland to release prolactin, initiating milk synthesis even in a woman who has not been pregnant.
