Journal Article

Breast Development in Transwomen After 1 Year of Cross-Sex Hormone Therapy: Results of a Prospective Multicenter Study

den Heijer, Martin, Nota, Nienke Marije, Klaver, Maartje, Wiepjes, Chantal Maria, Heijboer, Annemieke Corine, de Blok, Christel Josefa Maria, Schreiner, Thomas, T’Sjoen, Guy, Fisher, Alessandra Daphne

2018

Overview

Breast development is a key feature of feminization and therefore important to transwomen (male-to-female transgender persons). It is not exactly known when breast development starts after initiating cross-sex hormone therapy (CHT) and how much growth may be expected. To investigate breast development in transwomen during their first year of CHT and whether clinical or laboratory parameters predict breast development. This study was performed as part of the European Network for the Investigation of Gender Incongruence, which is a prospective multicenter cohort study. Gender clinics in Amsterdam, Ghent, and Florence. Transwomen who completed the first year of CHT (n = 229). CHT. Breast development in centimeter and cup size. The median age of the included transwomen was 28 years (range, 18 to 69). Mean breast-chest difference increased to 7.9 ± 3.1 cm after 1 year of CHT, mainly resulting in less than an AAA cup size (48.7%). Main breast development occurred in the first 6 months of therapy. Serum estradiol levels did not predict breast development after 1 year of CHT (first quartile, 3.6 cm [95% confidence interval (CI), 2.7 to 4.5], second quartile, 3.2 cm [95% CI, 2.3 to 4.2], third quartile, 4.4 cm [95% CI, 3.5 to 5.3], and fourth quartile, 3.6 cm [95% CI, 2.7 to 4.5]). This study shows that, after 1 year of CHT, breast development is modest and occurs primarily in the first 6 months. No clinical or laboratory parameters were found that predict breast development.

• Publisher: Oxford University Press
• Subject: 17β-Estradiol / Adolescent / Adult / Aged / Breast / Breast - drug effects / Breast - growth & development / Endocrine therapy / Female / Feminization - chemically induced / Feminization - physiopathology / Follow-Up Studies / Gender / Gonadal Steroid Hormones - therapeutic use / Humans / Laboratories / Male / Middle Aged / Physical growth / Sex hormones / Sex Reassignment Procedures - methods / Time Factors / Transgender Persons / Transsexualism - physiopathology / Transsexualism - therapy / Young Adult