Reproductive Desires and Gynaecological Organ Function in Transgender and Gender Diverse Individuals

Transgender and gender diverse (TGD) individuals experience incongruence between assigned sex at birth and their gender identity, which can significantly affect mental health. Gender-affirming treatment aims to align embodiment with identity, improving well-being, but often impacts fertility. Gonadectomy causes irreversible infertility, and hormone therapy may also compromise reproductive potential. Fertility preservation is therefore an important but complex consideration for those desiring biological parenthood. Chapter 1 introduces the historical evolution of transgender care in the Netherlands, from its start in the 1970s to current personalised approaches. Earlier requirements for sterility in legal gender recognition (abolished in 2014) highlight how rights and care have progressed. This change has underscored the need to improve fertility counselling and preservation options for TGD people. The thesis aims to address these gaps in research and practice. Chapter 2 presents a systematic review of 76 studies, showing that most TGD individuals express a strong desire for parenthood. However, access to fertility counselling and preservation remains limited, often due to restrictive laws and structural barriers. While sperm banking and oocyte vitrification are promising, uptake is low. The chapter stresses the need for equitable fertility care, better societal acceptance, and higher-quality research to counter misconceptions about TGD parenthood. Chapters 3 and 4 explore the perspectives of adults who began transition before the 2014 reforms. An online survey (Chapter 3, n=89) revealed that 96% became permanently infertile through gonadectomy, and none had undergone fertility preservation. More than half currently desire children, a marked increase compared to adolescence. Many regret not having been counselled more thoroughly about fertility. In-depth interviews (Chapter 4, n=21) highlighted six themes, including past considerations, current coping with infertility, and future family-building. Participants often expressed a wish for better information and support during adolescence. Chapter 5 shifts focus to individuals at the start of gender-affirming hormone therapy (GAHT), using data from the ENIGI study (n=666, 2017–2023). While most received fertility-related information, only 36% expressed parenthood desires, and fertility preservation rates were low (7% oocyte, 24% sperm cryopreservation). This shows that while awareness has increased, uptake of preservation remains limited. The next three chapters focus on transmasculine individuals. Chapter 6 reports on oocyte vitrification outcomes in both testosterone-naïve and prior users (who stopped treatment for three months). On average, 20 oocytes were retrieved and 17 vitrified, with high satisfaction despite burdensome hormone injections. Importantly, ovarian response did not differ by testosterone use history. Chapter 7 examines endometrial health. Transmasculine individuals on testosterone had thinner endometrium compared to cisgender women (3.9 mm vs. 4.9 mm). This suggests limited endometrial proliferation and indicates that routine ultrasound screening for asymptomatic individuals may not be necessary. Chapter 8 investigates ovulatory activity. Despite amenorrhoea, histological signs of ovulation were found in 33% of participants undergoing oophorectomy, independent of testosterone duration or levels. This challenges the assumption that amenorrhoea equals anovulation, underscoring the continued need for contraception. Chapter 9 concludes with a synthesis of findings, implications for clinical practice, and recommendations for future research. Collectively, the thesis highlights the importance of comprehensive, repeated fertility counselling, improved access to preservation options, and deeper investigation into the reproductive effects of testosterone use.