[Estrogen-progestin contraception. Disadvantages of estrogen reduction].

Over the past few years a number of new oral contraceptives have come into the market, with the following characteristics: reduced estrogen and progestin levels in order to reduce the incidence of cardiovascular disease, triphasic pills with maximum steroid concentrations coinciding with L.H. surge. These pills enable not only a reduction in progestin levels, but also in intercurrent bleeding. However, low steroid levels could lead to insufficient antigonadotropic effect with endogenous estrogenic secretion in some women. In fact, receptivity of targeted organs to sex steroids varies enormously between individuals. This partial inhibition of ovaries in some women poses problems of short and long term consequences: functional ovarian cysts; less protection than with traditional pills (50 micrograms ethinylestradiol) in terms of ovarian or endometrium cancer, benign breast disease... Only long term comparative and prospective studies, taking into account hormonal status and the degree of fertility and parity would enable the risks associated with these new contraceptives to be established. Consequently, in the light of our present knowledge, we recommend that low-dose oral contraception be avoided: when complete blockage of ovarian activity is required, in women with a history of ovarian cysts.