New study of the effects of feminizing hormones on testicular tissue in trans women

Most trans women on HRT are familiar with the phenomenon of “shrinkage”: atrophy of penile and testicular tissue, which typically becomes more pronounced the longer we’re on hormones. I’ve always wondered, as have many others, just what’s happening on the cellular level and what this really looks like. And a new study released this month provides an in-depth look at what, exactly, is being shrunk away here.

Kent et al. (2018) examined testicular tissue taken from 135 trans women who were undergoing either orchiectomy (removal of testes) or vaginoplasty at Mount Sinai Hospital. A majority had been taking estrogen along with an antiandrogen such as spironolactone, and these women were on HRT for an average of 7.9 years before surgery.

Notably, spermatogenesis – the production of sperm – was impaired or absent in the vast majority:

In total, 79% of patients (107/135) had no microscopic evidence of spermatogenesis on testicular pathology. Twenty-one percent (28/135) of specimens demonstrated some stage of spermatogenesis, including 4% (6/135) who had normal spermatogenesis in both testicles. Of those with impaired spermatogenesis, 61% (17/28) were in maturational arrest. Other less common findings included partial maturational arrest, few scattered spermatogonia, patchy spermatogenesis with surrounding fibrosis, and one individual had evidence of spermatogenesis in one testicle but not the other.

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About Zinnia Jones

My work focuses on insights to be found across transgender healthcare, public health, psychiatry, and history of medicine, integrating these many perspectives and guided by the lived experiences of trans people. I live in Orlando with my family, and work mainly in technical writing.
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