Breast asymmetry and phenotypic quality in women

Advances in general practice of medicine, 2022

Etiology of breast development and asymmetry is a fascinating research topic physiologically as well as pathophysiology from a certain condition. The shape, contour, and size of the breast are unique to each female. These factors are influenced by genetics, weight, exercise, menstruation cycles, pregnancy, menopause status, and age. An attempt was made to research the breast development at fetal development and transitioning into adulthood and menopause. Additionally, we compare breast development in males to the developments in females. Although breast asymmetry is experienced by all women, it ranges from grossly undetectable to the need for surgical intervention. It is thought that breast asymmetry has intrinsic and extrinsic factors that determine the type and the extent of asymmetry observed. Hormones at play and their effect on breast asymmetry throughout breast development has been charted. Breast asymmetry is most often secondary to benign breast disorders and unassociated with a risk for malignancy. As the perception of one's body image is an integral part of self-confidence, breast asymmetry has the potential to affect every woman's quality of life, regardless of the degree of asymmetry. Throughout this effort, our aim was to analyze and understand breast development in males and females, breast changes from the prepubertal to post-menopausal period, benign pathological changes, summarizing the etiologies of breast asymmetry, and their effects on quality of life.

Ethology and Sociobiology, 1995

Breasts of human females are large compared to those of closely related primate species, and they can thus be hypothesized recently or currently to have been subject to directional sexual selection. Here we show that (1) large breasts have higher levels of fluctuating asymmetry than small breasts, (2) breast fluctuating asymmetry is higher in women without children than in women with at least one child, (3) breast fluctuating symmetry is a reliable predictor of age-independent fecundity, and (4) breast fluctuating symmetry appears to be associated with sexual selection. These conclusions were similar in studies from two cultures differing in fecundity and brenstfeeding traditions (Spain; New Mexico, U.S.A.). Choosy males that prefer females with symmetrical breasts may experience a direct fitness benefit in terms of increased fecundity and an indirect benefit in terms of attractive or fecund daughters.

American journal of human biology : the official journal of the Human Biology Council, 2015

Breast size and fluctuating asymmetry (FA) are related to women's biological condition, as size correlates positively with fecundity, whereas FA correlates negatively with biological quality. We tested if breast volume, FA, and their changes during pregnancy are related to a fetus's sex. Women with bigger, symmetrical breasts, with a greater increase in size during pregnancy, should be more likely to carry a more ecologically sensitive and energetically demanding male fetus. Ninety-three women participated in a 3-stage longitudinal study. 3D breast scans were performed in the first, second, and third trimester of pregnancy. As there was a small variation in pregnancy week at each research stage between the participants, the expected breast volume and FA values for the 12th, 22nd, and 32nd pregnancy week were calculated, basing on the obtained measurements. Those values were compared between mothers who carried a boy and mothers who carried a girl. Although women who carried ...

The Breast Journal, 2011

Developmental breast asymmetry (DBA) can affect psychosocial well-being in the young female. Correction of breast asymmetry may present a reconstructive challenge, especially in tuberous breasts. Fifty-two cases of DBA treated between January 2002 and January 2006 were reviewed. Preoperative clinical assessment of the specific anatomical deformity, subsequent surgical treatment modalities, esthetic outcome, and patient's satisfaction were evaluated. Surgical modalities used in our series include augmentation mammaplasty with or without tissue expansion, parenchymal scoring, nipple areola complex reduction, glanduloplasty techniques, mastopexy and reduction mammaplasty. The mean age of DBA presentation was 21 years; 69% (36 ⁄ 52) patients had tuberous breasts, of which 67% (24 ⁄ 36) were unilateral and 33% (12 ⁄ 36) were bilateral deformities. Patients with tuberous breast deformity presented consistently under the age of 25 years. Esthetic outcome was rated ''good'' in 75% (39 ⁄ 52), and symmetry rated as ''good'' in 58% (30 ⁄ 52) by professional evaluation. Surgical treatment is tailored to the affected esthetic units of the individual breast. In our experience, symmetry is the hardest parameter to achieve, particularly in tuberous breasts. Operative treatment is of great value to the psychosocial well-being of the patient. A conceptual approach in the assessment and treatment of DBA is emphasized by this series. n

Evolution and Human Behavior, 2006

Fluctuating asymmetry (FA) is believed to reflect developmental stability and thus may serve as a marker of the biologic quality of individuals. To test the hypothesis that degree of FA is related to a woman's potential fertility, we measured finger length together with levels of estradiol in saliva samples collected daily for an entire menstrual cycle in 171 Polish urban and rural women. We show that women who are more symmetrical, as assessed by the degree of inequality in the fourth-digit length of their right and left hands, have 13% higher average levels of estradiol over the menstrual cycle than less symmetrical women (19.4 and 17.1 pmol/l, respectively; p =.0001). Among urban women, mid-cycle levels of estradiol were 28% higher in the symmetrical group than in the asymmetrical group. Because higher hormone levels in women may lead to a substantial rise in the probability of conception, low FA may therefore be associated with increased fertility. D

The British Journal of Radiology, 2019

Objective:Exposure to sex hormones is important in the pathogenesis of breast cancer and inability to tolerate such exposure may be reflected in increased asymmetrical growth of the breasts. This study aims to characterize, for the first time, asymmetry in breast volume (BV) and radiodense volume (DV) in a large ethnically diverse population.Methods:Automated measurements from digital raw mammographic images of 54,591 cancer-free participants (aged 47–73) in a UK breast screening programme were used to calculate absolute (cm3) and relative asymmetry in BV and DV. Logistic regression models were fitted to assess asymmetry associations with age and ethnicity.Results:BV and DV absolute asymmetry were positively correlated with the corresponding volumetric dimension (BV or DV). BV absolute asymmetry increased, whilst DV absolute asymmetry decreased, with increasing age (P-for-linear-trend <0.001 for both). Relative to Whites, Blacks had statistically significantly higher, and Chinese...

2010

T he objective of the current study was to investigate the heritability of breast size and the degree to which this heritability is shared with BMI. In a sample of 1010 females twins (mean age 35 years; SD = 2.1; range 28-40), self-report data pertaining to bra cup size and body mass index (BMI) was collected in the context of self-report data and an interview relating to disordered eating respectively. In a sample of 348 complete twin pairs who completed data collection (226 MZ pairs and 122 DZ pairs and 360 incomplete pairs (170 MZ and 190 DZ)), we found that the heritability of bra cup size was 56%. Of this genetic variance, one third is in common with genes influencing body mass index, and two thirds (41% of total variance) is unique to breast size, with some directional evidence of non-additive genetic variation. The implications of these findings with respect to previous research linking breast size with reproductive potential are discussed.

Breast Cancer: Basic and Clinical Research, 2015

The aim of this study was to investigate the criteria for determining the cancer risk of the breast asymmetry by comparing breast volume asymmetry levels between healthy women and women with cancer. MATERIALS AND METHODS: Two hundred and one women with breast cancer (group 1) were compared with 446 healthy women (group 2) who had no pathologic findings in breast sonography and mammograpy repeated with one-year interval. Data were evaluated retrospectively. Each breast volume was measured twice by Grossman-Roudner Discs. The mean value has been recorded. The amounts of volume difference between two breasts (asymmetry value) and the rates of the volume difference to the breast volume of the smaller side (asymmetry ratio) were compared in both groups. RESULTS: There was a statistically significant difference between two groups with regard to average age and body mass index (P  0.01). This significance was decreased but not disappeared, when the comparison was made within the 40-69 age group (P  0.01). The rate of cases with asymmetry value over 50 mL was significantly higher in the cancer group (P = 0.029). Unfortunately, it disappeared in the 40-69 age group (P = 0.201). The breast volume asymmetry ratio over 20% was significantly higher in the cancer group both in all ages and in the 40-69 age group (P  0.01). Odds ratio was 2.18 in the entire (all) series and 2.01 in the 40-69 age group. Moreover, there was no significant difference with regard to the rate of tumor location between the smaller or larger side of breast. CONCLUSION: Our data show that there is a positive correlation between breast asymmetry ratio over 20% and breast cancer risk. These results need to be confirmed by prospective randomized controlled trials.

Annals of Human Biology, 2019

Digit ratio (2d/4d) in humans is commonly used as a proxy for the exposure to oestrogens and androgens in prenatal life. Masculinisation/feminisation in adults may be also related to digit ratio and therefore to the oestrogen/androgen ratio in prenatal life. It has been shown, for instance, that Waistto-Hip ratio (WHR) and the amount and distribution of body fat are related to digit ratio in women. A species-specific, sexually dimorphic morphological trait in humans is also a pair of permanent breasts that develop during puberty, under the influence of oestrogens. Here we test if prenatal exposure to oestrogens (in relation to androgens), measured by digit ratio, may also be related to breast size in young, nulliparous women. 133 Turkish students (mean age 22.2) were measured. Breast size was calculated as the difference between breast and under-breast circumferences. We found that when controlling for body mass index (BMI), both right and left digit ratios correlate positively with breast size. This relationship is stronger for the digit ratio of the right hand, which confirms that this side is a better measure of sex differences. Thus, higher exposure to oestrogens in prenatal life is related with stronger expression of a sexually dimorphic trait, such as breast size, in adult women.

American …, 1986