ESPE Yearbook of Paediatric Endocrinology

Brief Summary: This study analyzed ovariectomy samples from 52 transmasculine individuals who had been using testosterone for >1 year (median 32, IQR 27–39 months) with serum concentrations in the male reference range. In one third (16/52) of the cohort, histological signs of recent ovulatory activity were observed, including the presence of ovulatory follicles, corpus luteum and corpus albicans. This was similar in the subgroup of 15 individuals who had previously used a GnRH analogue, discontinued at least 7 months prior to ovariectomy.

Testosterone treatment generally induces amenorrhea in transmasculine individuals. However, this study shows that ovulation may nonetheless occur. This underlines the importance of informing transgender individuals on testosterone therapy that there may be a chance of pregnancy despite amenorrhea and the need for contraception if they engage in sexual activity that can result in pregnancy. The findings are in line with that of a recent study using a mouse model of gender affirming treatment for adolescents (1). Mice were treated with leuprolide acetate and/or testosterone. 2/8 mice treated with testosterone showed evidence of cycling and a high number of corpora lutea on histology. That study also showed that eggs from mice treated with leuprolide acetate to prevent puberty and subsequently with testosterone, could be fertilized resulting in similar rates of live births to controls, and in fertile offspring (1). In humans, successful oocyte cryopreservation, fertilization and live birth as well as natural conception have also been reported in transmasculine persons after testosterone treatment albeit in small cohorts (2-4).

Together, these findings are reassuring with regard to the impact of gender-affirming hormone treatment on fertility in transmasculine individuals.

References: 1. Godiwala P, Uliasz TF, Lowther KM, Kaback D, Mehlmann LM. Puberty Suppression Followed by Testosterone Therapy Does Not Impair Reproductive Potential in Female Mice. Endocrinology. 2023 Sep 23;164(11):bqad145. doi: 10.1210/endocr/bqad145. PMID: 37768169.2. Leung A, Sakkas D, Pang S, Thornton K, Resetkova N. Assisted reproductive technology outcomes in female-to-male transgender patients compared with cisgender patients: a new frontier in reproductive medicine. Fertil Steril. 2019 Nov;112(5):858-865. doi: 10.1016/j.fertnstert.2019.07.014. Epub 2019 Oct 6. PMID: 31594633.3. Light AD, Obedin-Maliver J, Sevelius JM, Kerns JL. Transgender men who experienced pregnancy after female-to-male gender transitioning. Obstet Gynecol. 2014 Dec;124(6):1120-1127. doi: 10.1097/AOG.0000000000000540. PMID: 25415163.4. Asseler JD, Knieriem J, Huirne JA, Goddijn M, Verhoeven MO, van Mello NM. Outcomes of oocyte vitrification in trans masculine individuals. Reprod Biomed Online. 2023 Jul;47(1):94-101. doi: 10.1016/j.rbmo.2023.03.007. Epub 2023 Mar 14. PMID: 37095040.