Others have shown that the oral administration of diethylstilbestrol 25 mg daily for 5 days is an effective postcoital antifertility method. This dose of the estrogen was started in 4 volunteers on the day basal temperature rose. Endometrial carbonic anhydrase, 5 days after the temperature rise, was lowered to an average of 9.8 enzyme units (EU)/g as compared to the average control value of 21.2 EU/g. This decreased carbonic anhydrase activity may represent a barrier to implantation, although other antifertility mechanisms may also be activated by diethylstilbestrol.
© 1970 The American College of Obstetricians and Gynecologists