The creation and production of breast milk is an amazing feature of the female human body. The ability to feed our own young is thought to have contributed to the human race's continued adaptation to the world's climactic changes. In developing countries, where food is scarce and disease and illness is more prevalent, breast milk contributes to the survival of many newborn babies.
The following information describes how the female body develops and changes during the pregnancy to produce milk after the birth and how the baby 'milks the breast' to feed.
'Milking the breast'
When girls reach puberty, their breasts develop and enlarge under the influence of the hormone oestrogen. When a woman becomes pregnant, her breasts start to undergo further changes from about 4 to 6 weeks after the last menstrual period (or 2 to 4 weeks after conception), with the body producing greatly increased levels of progesterone and oestrogen. A woman's body cannot generally create mature breast milk until she has experienced at least 16 to 24 weeks of a pregnancy (this length of time varying between individual women).
The breasts of non-pregnant women are made up of two major structures. The smallest part is the underdeveloped glandular tissue, which is designed to grow and mature during pregnancy to eventually produce milk. The largest part is the supporting tissue that surrounds the glandular tissue. This incorporates smooth muscle, connective tissue, blood vessels, nerves, lymphlymph vessels and fat, covered by a layer of skin. Most of the breast tissue (that people associate with a woman having 'large' or small' breasts) comprises of the supporting tissues that surrounds the glandular tissue. This is why the 'size' of a woman's breasts has nothing to do with her ability to feed her baby.