ABSTRACT
CONTEXT: Breast development is an important outcome for trans women receiving gender affirming hormone therapy (GAHT). Limited breast development has been reported, possibly because of testosterone exposure during puberty. The impact of puberty suppression (PS) on breast development is unclear. OBJECTIVE: To investigate the impact of PS and timing of PS prior to GAHT on breast volume and satisfaction. DESIGN: Cross-sectional study. SETTING: Tertiary gender identity clinic. PARTICIPANTS: 60 trans women (aged 17-57 years) after 4.5±1.7 years of GAHT were included of whom 23 initiated PS early in puberty (Tanner stage G2-3), 17 late in puberty (Tanner stage G4-5), and 20 started GAHT in adulthood without prior PS. MAIN OUTCOME MEASURES: Breast volume measured with a 3D scanner and breast satisfaction measured with a questionnaire. Comparisons of breast volumes were adjusted for fat percentage. RESULTS: Median breast volume was 115ml (IQR 68; 203), i.e. bra cup-size
ABSTRACT
BACKGROUND: Feminizing gender-affirming hormone therapy (GAHT) for transgender individuals traditionally includes estradiol and androgen deprivation. Research has demonstrated that breast size as a result of GAHT in transgender women is often limited. Therefore, transgender women often choose to undergo breast augmentation surgery. Progesterone is important for breast development in cisgender women during puberty. A potential role for progesterone in breast development in transgender women has not been investigated in a randomized controlled experimental set-up. The primary objective of this study is to explore the effects on breast volume of addition of oral progesterone to GAHT with estradiol in transgender women after vaginoplasty or orchiectomy. Secondary objectives include assessment of safety, satisfaction, mood, sleep and sexual pleasure. METHODS: This is a non-blinded, non-placebo, randomized controlled trial using a factorial design in adult transgender individuals assigned male sex at birth who have undergone GAHT for at least one year and underwent vaginoplasty or orchiectomy. The study design allows for rapid assessment of potential synergistic effects of various dose combinations of estradiol and progesterone on breast volume change: Ninety participants will be randomized into six groups of 15 subjects each, receiving either the baseline dose of estradiol, the baseline dose of estradiol and progesterone 200 mg daily, the baseline dose of estradiol and progesterone 400 mg daily, twice the baseline dose of estradiol, twice the baseline dose of estradiol and progesterone 200 mg daily or twice the baseline dose of estradiol and progesterone 400 mg daily, all for a duration of 12 months. The main study parameters include changes in breast volume as determined by 3D measurements. Participants will be followed-up with laboratory testing including serum progesterone concentrations as well as surveys for satisfaction, mood, sleep quality and sexual pleasure. DISCUSSION: This study will indicate whether progesterone is safe and of additional value with regard to breast volume change in transgender individuals receiving feminizing GAHT. The results of this study will be useful for innovation of feminizing GAHT. TRIAL REGISTRATION: WHO International Clinical Trials Registry Platform: EUCTR2020-001952-16-NL; date of registration: 12 December 2020 https://trialsearch.who.int/Trial2.aspx?TrialID=EUCTR2020-001952-16-NL .