It is normal for the breasts to enlarge duringpregnancy.
Normal histology of the breast during lactation.
Mammoplasia is the normal or spontaneousenlargement of human breasts.[1] Mammoplasia occurs normally duringpuberty andpregnancy in women, as well as during certain periods of themenstrual cycle.[2][3][4] When it occurs in males, it is calledgynecomastia and is considered to bepathological.[4] When it occurs in females and is extremely excessive, it is calledmacromastia (also known as gigantomastia orbreast hypertrophy) and is similarly considered to be pathological.[5][6][7] Mammoplasia may be due tobreast engorgement, which is temporary enlargement of the breasts caused by the production and storage ofbreast milk in association withlactation and/orgalactorrhea (excessive or inappropriate production of milk).[8]Mastodynia (breast tenderness/pain) frequently co-occurs with mammoplasia.[9][10]
A 1997 study found an association between the SSRIs and mammoplasia in 23 (39%) of its 59 female participants.[26] Studies have also found associations between SSRIs and galactorrhea.[24][28][29][30] These side effects seem to be due tohyperprolactinemia (elevated prolactin levels) induced by these drugs, an effect that appears to be caused byserotonin-mediated inhibition oftuberoinfundibulardopaminergicneurons that inhibit prolactin secretion.[26][28][29] The mammoplasia these drugs can cause has been found to be highly correlated with concomitantweight gain (in the 1997 study, 83% of those who experienced weight gain also experienced mammoplasia, while only 30% of those who did not experience weight gain experienced mammoplasia).[26] The mammoplasia associated with SSRIs is reported to be reversible with drug discontinuation.[30] SSRIs have notably been associated with a modestly increased risk ofbreast cancer.[31] This is in accordance with higher prolactin levels being associated with increased breast cancer risk.[32][33]
^Arnold G. Coran; Anthony Caldamone; N. Scott Adzick; Thomas M. Krummel; Jean-Martin Laberge; Robert Shamberger (25 January 2012).Pediatric Surgery. Elsevier Health Sciences. pp. 773–.ISBN978-0-323-09161-9.
^Ruth A. Lawrence; Robert M. Lawrence (26 October 2015).Breastfeeding: A Guide for the Medical Profession. Elsevier Health Sciences. p. 60.ISBN978-0-323-35776-0.The cyclic changes of the adult mammary gland can be associated with the menstrual cycle and the hormonal changes that control that cycle. Estrogens stimulate parenchymal proliferation, with formulation of epithelial sprouts. This hyperplasia continues into the secretory phase of the cycle. Anatomically, when the corpus luteum provides increased amounts of estrogen and progesterone, there is lobular edema, thickening of the epithelial basal membrane, and secretory material in the alveolar lumen. Lymphoid and plasma cells infiltrate the stroma. Clinically, mammary blood flow increases in this luteal phase. This increased flow is experienced by women as fullness, heaviness, and turgescence. The breast may become nodular because of interlobular edema and ductular-acinar growth.
^Milligan D, Drife JO, Short RV (1975)."Changes in breast volume during normal menstrual cycle and after oral contraceptives".Br Med J.4 (5995):494–6.doi:10.1136/bmj.4.5995.494.PMC1675650.PMID1192144.[M]any women report breast changes during the normal menstrual cycle, with a feeling of fullness and a tingling sensation immediately before menstruation.1 Women taking oral contraceptives also seem to experience similar breast symptoms.2 It has been claimed that there are also pronounced changes in breast volume during the normal menstrual cycle, with maximum values occurring in the week before menstruation.3
^Dancey, Anne; Khan, M.; Dawson, J.; Peart, F. (2008). "Gigantomastia – a classification and review of the literature".Journal of Plastic, Reconstructive & Aesthetic Surgery.61 (5):493–502.doi:10.1016/j.bjps.2007.10.041.ISSN1748-6815.PMID18054304.
^de Muinck Keizer-Schrama SM (2007). "Introduction and management of puberty in girls".Horm. Res. 68 Suppl 5 (5):80–3.doi:10.1159/000110584.PMID18174716.