Bloch S K
Am J Obstet Gynecol. 1975 Apr 15;121(8):1021-2. doi: 10.1016/s0002-9378(16)33583-9.
Serum luteinizing hormone (LH) values determined by radioimmunoassay can be of aid in evaluating patients with short-term amenorrhea. These values have proved useful in ruling out pregnancy in cases of hypothalamic amenorrhea and amenorrhea occuring during treatment with contraceptive pills and also in diagnosing early pregnancy after clomiphene therapy.