Effect of emergency contraception (ulipristal acetate) on growth, sexual differentiation, and reproduction in Oryzias latipes.

Pharmaceuticals used to relieve symptoms of human illnesses may not be completely removed by sewage treatment facilities, resulting in environmental runoff. Pharmaceuticals leaking into the environment can adversely affect wildlife. Ulipristal acetate (UPA), an emergency contraceptive (EC), is used both as EC and to treat uterine fibroids. This study aimed to clarify the effects of UPA on the growth, sexual differentiation, and reproduction of Japanese medaka. No statistically significant difference was observed in the hatching rate, growth, or reproduction between the control and UPA-exposed groups. In addition, investigation of the effect of UPA on sexual differentiation of Japanese medaka revealed no individuals with testis-ova or ovo-testis or individuals with sex change at concentrations of 1, 10, or 100 µg/L. This study is the first to examine the effects of UPA on growth, gonadal sex differentiation, and reproduction in fish. Our results indicate that UPA has no effect on Japanese medaka and is thus an ecosystem-friendly emergency contraceptive.