Synthetic estrogen that has a similar action as estradiol. Used in combination with progestogens for contraception. Ethinylestradiol is excreted in small or no amount into breast milk.There is evidence (albeit inconsistent) that estrogen-containing pills may decrease milk production, especially during the first few weeks postpartum with a daily dose above 30 micrograms of ethinyl estradiol.It may reduce the protein content of the milk.No problems have been observed in infants whose mothers were treated, except some cases of transient gynecomastia in infants whose mothers were receiving a higher dose than usual. During lactation progestin-only drugs are preferred or in combination with estrogen for birth control, but whatever, the ones with the lower doses of estrogen should be used.For the first 6 weeks postpartum, non-hormonal methods are of choise.