Currently, the three available methods for the early detection of breast cancer include mammography, clinical breast examination, and breast self-examination. Childbirth education instructors are thus in a unique position to encourage this important health promotion strategy at a time in life when women and their partners are responsive to learning. The female breast is composed of glandular and fibrous tissue as well as subcutaneous and retromammary fat. The glandular tissue of each breast consists of fifteen to twenty lobes arranged in a spoke-like pattern around the nipple. Contraction of the smooth muscles of the nipple, induced by tactile, sensory, or autonomic stimuli, causes the lactiferous ducts to empty.
Pregnancy leads to striking changes in the breasts.
In response to luteal and placental hormones, there is a proliferation of the lactiferous ducts and an increase in both the number and size of the acini cells. Breast size and consistency change throughout pregnancy as a direct result of this increased proliferation of glandular tissue and its resultant displacement of the supportive connective tissue of the breast. Thus the breast may increase two to three times its pre-pregnancy size and the tissue may become softer and looser. The blood supply to the breast also increases during pregnancy, causing veins to engorge and be visible as a blue network below the skin's surface. In the initial few days following delivery, small amounts of colostrum are secreted from the breast.