To the editor: In view of the correspondence between Drs. Paulshock, Andersen, and Hayman and particularly Dr. Hayman’s statement,
“I know of no reports in the literature showing that estrogen has been administered to humans directly after insemination and has prevented nidation”
(Ann Intern Med 72:961, 1970), it might be worth calling your readers’ attention to the two articles from our Department. I believe the doses of estrogen suggested by Drs. Paulshock and Andersen are too small to give consistent protection against pregnancy.
Fifty milligrams of diethylstilbestrol (Stilbestrol®) a day for 5 days appears to be effective; 20 mg of premarin, intravenously, has also been used with success.
As these are actually postovulatory rather than postcoital contraceptives, timing is of the greatest importance, especially if there has been more than one exposure during the cycle.