Khatchadourian, Amed, & Metzger (2014) found that among 63 trans girls and boys receiving cross-sex hormone therapy in adolescence, no cases of serious side effects such as thrombosis were reported. A recent abstract of a study by Kowalczyk Mullins et al. (2020) at the Cincinnati Children’s Hospital Medical Center reports the frequency of thrombosis observed among 635 trans adolescents and young adults aged 13-24 receiving estrogen or testosterone treatment. How many experienced thrombosis during this treatment? Zero.
None of the 635 patients developed clinically significant thrombosis. One patient experienced recurrent superficial thrombophlebitis associated with peripheral intravenous catheters.
Three patients had a history of previous thrombosis and two were on prophylactic anti-clotting treatment; another three were started on anti-clotting treatment upon initiating HRT due to risk factors for thrombosis. Nonetheless, neither these patients nor any others experienced thrombosis during cross-sex hormone therapy. The authors recommend:
Clinicians should 1) obtain a careful and detailed personal and family history of risk factors for and history of thrombosis and consider referral to a hematologist to discuss the risks associated with GAHT, and 2) counsel about modifiable risk factors such as tobacco use and obesity.
At a time when multiple state legislatures are moving to prohibit the administration of puberty blockers and cross-sex hormones to trans adolescents, studies such as these are essential to establishing the basic safety of these treatments. Medical transition in adolescence is beneficial to trans youth, necessary for their well-being, and, as this latest study indicates, low-risk and safe. ■