Oral contraceptive steroids and breast secretions.

Breast secretions were obtained by nipple aspiration from 164 (44.7%) of 368 consecutive premenopausal non-pregnant women volunteers attending family planning clinics. Women currently taking oral contraceptive steroids were significantly less likely to yield breast secretions than women who had never taken such preparations. The effect was confined to parous women of whom 94% not taking oral contraceptives yielded breast secretions compared with only 51% currently using the pill and 60% of those with a previous history of use. The percentage of nulliparous women yielding breast secretions (30%) was significantly less than that in parous women and was not affected by a present or previous history of contraceptive steroid use. These results provide further evidence of the difference in hormone responsiveness of parous and nulliparous breasts and the potential of oral contraceptive steroids to influence breast function.