Differences in Chest Measurements between the Cis-female and Trans-female Chest Exposed to Estrogen and Its...

Gender confirming primary breast augmentation is becoming more common. The purpose of this study was to compare the demographic and anatomical differences in cis-female and trans-female populations.

This was a retrospective analysis of trans-female patients and cis-female patients undergoing primary breast augmentation at a single institution. Analysis included patient demographics and preoperative chest measurements including sternal notch to nipple distance (SSN), breast width (BW), nipple to inframammary fold distance (N-IMF), and nipple to midline distance (N-M). Continuous variables were compared using independent t tests, and discrete variables were compared using Pearson's χ² tests.

Eighty-two trans-female and 188 cis-female patients undergoing primary breast augmentation were included. Trans-female patients were older (40.37 versus 34.07), more likely to have psychological comorbidities (50% versus 12.23%), and had a higher body mass index, 27.46 kg/m² versus 22.88 kg/m² (P = 1.91E-07), than cis-female patients. Cis-female patients most commonly had an ectomorph body habitus (52% versus 26%), whereas trans-female patients most commonly had an endomorph body habitus (40% versus 7%). Pseudoptosis or ptosis was more commonly seen in cis-female patients (P = 0.0056). There were significant differences in preoperative breast measurements including sternal notch to nipple distance, BW, and N-M between groups, but not in N-IMF. The ratio of BW/N-IMF was statistically significant (P = 2.65E-07 on right), indicating that the similarity in N-IMF distance did not adjust for the difference in BW.

The trans-female and cis-female populations seeking primary breast augmentation have significant demographic and anatomical differences. This has implications for surgical decision-making and planning to optimize outcomes for trans-female patients.