Lactation is a natural process that produces milk in your breasts. Milk is secreted through the mammary glands through hormonal influence. The lactation process however starts from the twenty-fourth week of the pregnancy during the second and third trimester.
Hormones such as Progestrone, Oestrogen and Prolactin are released into the body. Each of these hormones has a specific function. Progrestrone is responsible for growth in size of alveoli and lobes and it also stops the lactation process from happening, before the birth. As the time nears for the baby’s birth, the Progrestrone levels in the body drops to make way for the milk ducts to start working!
Oestrogen is the hormone that is secreted to stimulate the milk duct system to produce. Similar to Progrestrone, high levels of Oestrogren inhibits milk production.
Prolactin is the hormone that influences the differentiation of ductal structures. In other words, this hormone regulates the milk production and maintains the balance between supply and demand.
With all these hormones secreted, your breasts are ready to produce milk for its child by the sixth month of pregnancy.
During the third trimester, your breasts will start producing Colostrum and this is when you enter a stage called Lactogenesis I. Colostrum is the foremilk that is secreted during the lactation process. This thick yellowish liquid may not resemble milk but it is essential for the babies to feed on it. Colostrum has many important antibodies that will protect the baby from infection and diseases. Some women in their later stages of pregnancy release colostrum. If this is happening to you, there is no cause for concern. You will have enough colostrum when the baby is born so there is no need to worry.
The next stage in the lactation process is the birth of the child. Every hormone has a part to play during this process. Your Prolactin hormone levels will remain high during the entire process since it is preparing your breasts for the milk production. And as soon as your placenta is removed, your hormone levels for Progestrone, Oestrogen and HPL will drop so as to start producing the milk for the baby. This is when you will be in a stage called Lactogenesis II. At this stage the Prolactin levels will rise and the alveoli will start making milk. Theoretically, the milk production will start, but most often it will take atleast 48 hours for your breasts to fill with milk. Until then, you can feed your colostrum to the baby.
The last stage of the lactation is called Lactogenesis III. Once your baby forms a normal feeding routine, the Lactogenesis III stage begins. In this stage, the milk production is as per the supply and demand. As and when the baby feeds at your breast, more milk will be produced.
The hormone Oxytocin also plays an important role in the lactation process. This hormone is responsible for the ‘milk let-down’ or ‘milk ejection’. It is a reflex action and it can be triggered when the baby starts crying. Oxytocin is responsible for stimulating muscles around the breast, which is when they start leaking as soon as your baby cries.