"Normal" breast dimensions in obese women-reference values and the effect of weight loss.

[BACKGROUND] Breast hypertrophy may cause significant suffering, such as back- and breast pain, painful shoulder groves, and eczemas. Furthermore, women with breast hypertrophy may have lower quality of life than women without breast hypertrophy. Although 50% of the women undergoing breast reduction in the US have body mass index (BMI) >30 kg/m, the current standard of normality is based on studies focusing on women <40 years of age and BMIs <25 kg/m. This study aimed to present reference values for breast measurements for women with obesity and to investigate the relationship between BMI loss and each breast measurement.

[MATERIALS AND METHODS] One hundred and six women underwent laparoscopic Roux-en-Y gastric bypass in Gothenburg, Sweden. The participants' breast anthropometrics were measured before and after bariatric surgery and their perception of the skin on their breasts was measured using the Sahlgrenska Excess Skin Questionnaire.

[RESULTS] Breast volume, sternal notch to nipple (SNN) distance, and ptosis increased significantly with increasing BMI. For instance, women with BMIs between 30-34.9 kg/m have a mean breast volume of approximately 770 ml, those with BMIs of 40-44.9 kg/m have approximately 1150 ml, and those with BMIs above 50 kg/m have approximately 1400 ml. Furthermore, the percent change in the respective breast measurements relative to percent BMI change can be predicted, for instance, with a 20% reduction in BMI, the breast volume, SNN-distance, and ptosis decrease by 25%, 4%, and 20% respectively.

[CONCLUSIONS] This article presents the first standard of normality for breast anthropometrics in women with obesity and a model for predicting the change in breast anthropometrics relative to BMI.

[CLINICAL TRIAL REGISTRATION] This is a longitudinal observation study, registered https://fou.nu/is/gsb/ansokan/49651, No: VGFOUGSB-49651. Trial registry name: "Överskottshud efter överviktskirurgi - dess utveckling samt behov och effekt av plastikkirurgi" ("Excess skin after bariatric surgery - its development and the need and effect of plastic surgery").