Lactation: Process, Preparation and Hormones

Lactation: The more we know about human breast milk, the more we discover its value in human nutrition and development. Do you know the importance of milk? Have you heard the term breastfeeding? Breastfeeding is the process of feeding newborn babies with milk that is produced from the mother’s mammary glands. This stage, known as Lactation, is developed after a few months of pregnancy. Lactation, the process of producing milk, occurs in all mammalian species.

What is Lactation Period?

The production and release of milk from the mammary glands after birth by a woman is known as lactation.

Fig: Lactation

What is Colostrum?

The first milk which comes out from the mother’s mammary glands just after childbirth is known as colostrum or foremilk. It is a breast fluid produced by humans, cows, and other mammals before breast milk is released.

Fig: Colostrum

Colostrum is yellow coloured, rich in proteins (lactalbumin and lactoprotein) and energy, along with antibodies that provide passive immunity for newborn babies. It is interesting to note that Bovine colostrum (bovine = related to cow) is similar to human colostrum and is rich in several vitamins, minerals, fats, carbohydrates, disease-fighting proteins, growth hormones, and digestive enzymes. Human colostrum is rich in macronutrients, vitamins, and minerals. Several types of proteins are found in the human colostrum, which is essential for the infant’s health, like:

1. Lactoferrin protein promotes the immune system of the baby.
2. Typically, IgG (Immunoglobulin G) is present in the human colostrum, which provides basic immunity to the infant. Bovine colostrum also contains other antibodies like IgA and IgM.
3. Certain growth factors are also reported to be present in colostrum. Bovine colostrum is a rich source of insulin-like growth factors \(1\) and \(2\) (IGF-\(1,\) IGF-\(2\)).

Milk synthesis is stimulated by the pituitary hormone called Prolactin. The release of milk is stimulated by a rise in the level of the oxytocin hormone when the baby begins to nourish. Milk contains inhibitory peptides that accumulate and inhibit milk production if the breasts are not fully emptied.

Preparation for Lactation

i. Usually, a female or a mother is ready to produce milk during her fifth or sixth month of pregnancy.
ii. During the upcoming stages of pregnancy, a female enters the first stage of lactogenesis.
iii. At this stage of pregnancy, a woman’s breast produces a thick yellow coloured fluid called Colostrum that is extremely nutritious and rich in all vital components like fats, sugar, vitamins, minerals and enzymes necessary for efficient digestion.
iv. It is of harmful proteins which can trigger allergies. It also contains antibodies for protection against diseases like gastric and respiratory diseases.

What is the Process of Lactation?

The process by which milk is formed in a woman’s breast is known as the lactation process. The lactation process takes place as follows:

i. The breast starts growing during the period of pregnancy because of the impact of ovarian and placental hormones. It continues to get larger even after childbirth.
ii. Secretion and storage of milk begin after the birth of the young one, usually within \(24\) hrs, under the influence of prolactin.
iii. The amount of milk secretion increases after the delivery.
iv. The milk is secreted from the mothers’ mammary gland itself during the process of lactation.

Lactation Hormones

During the lactation period, certain hormones play an important role. Those hormones are estrogen, placental lactogenic, progesterone, prolactin and oxytocin. Oxytocin and Prolactin are the major hormones involved in the lactation process.

i. Oestrogen Hormone – This hormone helps in increasing the size of the breast during pregnancy, causing the growth of breast tissue.
ii. Placental Lactogenic Hormone – This hormone will be higher during the pregnancy period as this hormone helps in stimulating the growth of nipples, areola and breast tissues.
iii. Progesterone Hormone – This hormone helps in increasing the size of the breast tissue along with boosting milk production in the woman. This progesterone hormone level tends to decrease during the post-pregnancy period, which helps in stimulating milk production.
iv. Prolactin Hormone – The hormones called prolactin hormone helps in differentiating the cells that perform their specific functions. Due to the influence of prolactin hormone, the alveoli start producing milk after the birth of the baby. The prolactin hormone is produced under the influence of the cortisol hormone.
v. Oxytocin Hormone – The actual release of milk, called milk letdown, requires the presence of oxytocin, which brings about the contraction of the smooth muscles of the ducts within the mammary glands. Secretion of Prolactin and oxytocin depends on the sucking stimuli produced by the nursing infant on the nipples of the breasts.

Lactational Amenorrhoea

The lactational amenorrhoea describes the absence of menstruation during lactation. This is one of the natural methods of birth control in human beings. Suckling affects the release of Gonadotropin-releasing hormone (GnRH) of the hypothalamus and other pituitary hormones, like a follicle-stimulating hormone and luteinizing hormone. This is a negative feedback mechanism. The elevated level of prolactin hormone in the blood of the mother produces such inhibitory effects. When follicle growth and oestradiol secretion does increase to the normal level, during lactation, the generation of a normal preovulatory LH surge is prevented, and the follicles fail to rupture. These effects together result in the suppression of ovulation and menstruation. Therefore, frequent breastfeeding can help to delay a new pregnancy.

Importance of Breastfeeding

Breastfeeding is very important for a baby to be strong and healthy. Milk contains an inhibitory peptide, and if the mammary glands are not fully emptied, the peptide accumulates and inhibits milk production in the mothers.

Is Lactation Possible Without Pregnancy?

Yes, Lactation can happen without pregnancy or in non-pregnant women. There are three hormones that play a very important role in stimulating milk production in the mammary glands of a lactating mother. Consuming medicines containing these three hormones in the form of supplements would help any woman to produce breast milk in their mammary glands without pregnancy.
There are certain other situations where lactation can happen without pregnancy. They are as follows:
i. Health disorders
ii. Side effects of drugs or medicines
iii. Overproduction of prolactin hormone in the brain
iv. Nerve irritation in the breast region.

Properties of a Lactating Milk

i. The milk produced in the initial phase of lactation varies from the milk after maturation. The milk produced during the lactation period is well established.
ii. The protein-rich, yellow coloured milk called colostrum is the milk that is produced in the initial phases of lactation.
iii. The composition of the milk changes gradually after the process of childbirth. The colostrum changes to transitional milk within four to five days from childbirth.
iv. After \(14\) to \(15\) days of childbirth, the matured milk is produced in the mammary glands of a woman.
v. Later, when the baby gradually decreases the demand for milk, the lactation process also decreases.

Nutritional Requirement During Lactation

A lactating mother should always consume nutritious food during lactating the infants. It is also equally important for babies to get good nutrition. Hence, there are certain guidelines that should be followed in the diet of a lactating mother. Taking the right amount of nutrients will help the mother and the child to be healthy. The nutrients that a lactating mother should follow are given in the table below.

Effect of Drugs and Alcohols During Lactation

Both drugs and alcohol affect lactation and, eventually, the health of the infant. It is found that many drugs are secreted in breast milk, and smoking reduces breast milk volume and decreases infant growth rates. It is also interesting to note that alcohol can be detected in breast milk for about \(2\) to \(3\) hours per drink after it is consumed. The highest quantity of alcohol is detected in breast milk \(30-60\) minutes after consumption. Maternal use of oral narcotics, like morphine, opiates, during breastfeeding can cause severe drowsiness in the infants, central nervous system depression and even death.

Summary

Lactation can be described as the process of secretion of milk from the mammary glands after birth by a woman. Breastfeeding is very important for a baby to be fit and healthy. The consumption of human milk confer unique nutritional and non-nutritional benefits to the infants and the mother and, in turn, optimize infant, child and adult health as well as child growth and development.

Through this article, we understood the importance of milk, which is the exclusive source of nutrients and energy for infants and how lactation is carried out from the involvement of certain specific hormones. We also understood the process of lactation from this article.

Frequently Asked Questions (FAQs) on Lactation

The answers to the most commonly asked questions about Lactation are provided here:

We hope this detailed article on Lactation helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.