Transdermal versus oral hormone therapy in premature ovarian insufficiency

Objectives: Hormone therapy is recommended in women with premature ovarian insufficiency to mitigate long-term risks associated with estrogen deficiency, such as loss of bone mineral density. However, data on the optimal route of administration are scarce. This study aimed to compare the effect of transdermal and oral hormone therapies on the T-scores of the femur and the hip in women with premature ovarian insufficiency. Methods: This retrospective, single-center cohort study included 55 women with spontaneous premature ovarian insufficiency who were regularly monitored at the Clinical Division of Gynecological Endocrinology and Reproductive Medicine of the Medical University of Vienna. For hormone therapy, participants received either oral or transdermal estrogen therapy. The main outcome parameters were the T-scores of the femur and hip assessed by dual-energy x-ray absorptiometry scans. Results: Among the 55 women included [median age: 34 y, interquartile range (IQR): 27-36], 65.5% showed reduced bone mineral density in the dual-energy x-ray absorptiometry scan results (osteopenia: n= 27, 49.1%; osteoporosis: n= 9, 16.4%). Participants were treated with transdermal and oral estradiol in 27 (49.1%) and 28 cases (50.9%), respectively. There were no significant differences in the T-scores of the femur and the hip, neither at baseline ( P =0.586, P =0.400) nor at follow-up assessment ( P =0.618, P =0.471) between the two treatment groups. Conclusions: Both oral and transdermal hormone therapies effectively help maintain bone mineral density in women with premature ovarian insufficiency, indicating that either option is a suitable treatment choice for this population.