35 cycles with spontaneous luteinizing hormone ( lh ) surges were compared with 29 control cycles with respect to serum fsh and estradiol ( e2 ) levels drawn on the day prior to and the day of human chorionic gonadotropin ( hcg ) , approximately 16 hr after gonadotropin stimulation .
C0018062
human chorionic gonadotropin
C0018061
gonadotropin