Trends in the use of oral contraceptives and progestins in Japanese female Olympic athletes.

OBJECTIVES

Long-term trends in the use of oral contraceptives or progestin preparations in elite female athletes and the types of hormonal preparations are unclear. This study aimed to examine longitudinal changes in the prevalence and types of hormonal preparations used by Japanese female Olympians over 16 years.

METHODS

This retrospective cohort study analyzed pre-participation medical examination questionnaires, including age, sport, and whether participants were taking prescribed hormonal preparations, from all Japanese female athletes selected for nine consecutive Olympic Games (Beijing 2008-Paris 2024). Data on the use and specific type of oral contraceptives (OCs) and progestin-only preparations were extracted. Temporal trends were assessed using weighted logistic regression models.

RESULTS

The total number of female athletes who competed in the past nine Olympic Games was 1,227. The prevalence of hormonal preparation use increased more than six-fold, from 4.7% at Beijing 2008 to a peak of 36.0% at Beijing 2022 (29.3% at Paris 2024). A weighted logistic regression confirmed a significant trend, with the odds of use increasing 1.67-fold per four-year Olympic cycle (95% CI 1.48-1.89, p < 0.001). A significant shift occurred from OCs containing ≥30 µg of ethinylestradiol (EE) to those containing 20 µg of EE, and from desogestrel-based OCs to those containing drospirenone and norethisterone. Progestin-only preparations were first reported at Rio 2016, with their use increasing thereafter.

CONCLUSION

The number of elite-level female athletes in Japan using hormone preparations has increased significantly over the past 16 years, and the types of preparations used have also diversified. This trend highlights the growing importance of gynecological support in elite sports. Future research should focus on the potential performance and health effects of the newer-generation formulations that are now predominantly used.