Co-cyprindiol (ethinylestradiol and cyproterone acetate; Dianette®, Clairette®) is indicated primarily for acne or hirsutism but it is also contraceptive and concerns have been raised about fetal exposure to cyproterone acetate. The SPC for Dianette29 advises that pregnancy must be excluded before treatment is begun, and states that animal studies have revealed that feminisation of male fetuses may occur if cyproterone acetate is administered during the phase of embryogenesis at which differentiation of the external genitalia occurs. Although the results of these tests are not necessarily relevant to man, the possibility must be considered that administration of Dianette to women after the 45th day of pregnancy could cause feminisation.
