General information
The female breast consists of muscles, connective tissue, nerves, blood and lymph vessels, fatty tissue, glands and milk ducts. Many women notice changes in their breasts as the first sign of pregnancy. Due to the hormonal changes in the body and the resulting enlargement of glandular tissue and milk ducts and increased blood circulation, the breasts become larger and can react sensitively to touch.
Many women already know these symptoms as part of their normal monthly cycle. In contrast, however, the changes in the breasts are usually more pronounced during pregnancy. During pregnancy, the breast changes continuously.
In the first trimester of pregnancy (first to twelfth week of pregnancy (SSW)), the growth of the breast is in the foreground for many women due to the strong increase in hormones. In the second third of pregnancy (13th to 28th week of pregnancy) the speed of growth decreases slightly. The nipples may appear somewhat darker and in some cases, from this stage of pregnancy onwards, foremilk, the so-called colostrum, may leak out.
In the third trimester (29th to 40th week of pregnancy) the breast actively prepares for breastfeeding. The actual milk discharge usually follows a few days after birth. However, the changes in the breast during pregnancy vary from woman to woman.
Causes
Especially the hormonal changes during pregnancy have an impact on the changes of the whole body and especially on changes of the breast. Among the hormones that are produced in increased quantities during and after pregnancy are the female sex hormones estrogen and progesterone, as well as human chorionic gonadotropin (HCG), prolactin and oxytocin. Oestrogen, progesterone, prolactin and oxytocin play an important role in the changes in the breast during pregnancy. Oestrogen and progesterone lead to an increase in the number of mammary gland ducts and thus to increased breast growth. Prolactin and oxytocin cause the milk to be absorbed, milk production and milk transport during breastfeeding.
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