Failure to induce early abortion by huge doses of a superactive LRH agonist in women.

The possible abortifacient effect of the potent stimulatory luteinizing hormone-releasing hormone analogue D-Ser(TBU)6-EA10-LRH was studied in five women in early pregnancy. Four of them were treated by intravenous injections of the superactive LRH agonist in a dose of 50-125 micrograms t.i.d. for four days (total dose 600-1500 micrograms). The fifth woman discontinued treatment after the first 50 micrograms dose. The treatment was instituted on gestational day 37, 38, 40, 42 and 46. Clinical examinations and frequently taken peripheral venous blood samples for analyses of human chorionic gonadotropin and ovarian steroids were used for monitoring the treatment. No abortifacient effects of these large doses of the superactive LRH agonist were observed and the pregnancies had to be terminated by suction curettage after 10-13 days. Thus, previously described luteolytic effects by superactive LRH agonist are overcome probably by endogenous chorionic gonadotropin in early human pregnancy.