The Effects of Chorionic Gonadotropin and Prolactin on the Maintenance of Corpus Luteum Function*†

Physiology and Genetics of Reproduction

“…Measurement of gonadotropin and steroid hormones in presumptive ovulatory menstrual cycles during which conception did not occur demonstrated that levels of these three steroid hormones all begin to decrease about 10 days after the midcycle LH peak . If a constant amount of exogenous HCG is injected into women daily or thrice weekly beginning in the early or middle luteal phase of the cycle, the onset of menses can be delayed for about 2 wk (Brown and Bradbury, 1947;Freid and Rakoff, 1951). However, the HCG injections have to be initiated prior to 10 days after ovulation to prevent degeneration of the corpus luteum.…”

“…However, the HCG injections have to be initiated prior to 10 days after ovulation to prevent degeneration of the corpus luteum. Freid and Rakoff (1951) gave daily injections of HCG during the 4 days preceding the anticipated date of menses and failed to alter the date or type of menstrual flow. In this study, a clearly definable increase in radioimmunoassayable LH-HCG above baseline luteal phase levels was initially observed 11 or more days after the LH peak, yet steroid levels had not previously begun to decrease.…”

Antiprogestins

“…It has been known for some time (Brown and Bradbury 1947;Fried and Rakoff 1952) that women experience pseudopregnancy if HCG is administered continuously after the 20th day of the cycle to prolong the 'action of the corpus luteum. Daily doses of 5,000 IU HCG or more are required to prolong the action of the corpus luteum over 13 days; this can be monitored by recording the excretion of pregnandiol and the length of cycle.…”

Progesterone content of bovine reproductive organs during pregnancy

“…In pri mates the chorionic gonadotrophin appears to maintain the corpus luteum in early stages of pregnancy. Fried and Rakoff (1952 ) suggested that lactogenic hormone in synergism with luteinizing hormone had luteotrophic properties in the human. They were able to prolong the function of the cornus luteum by injecting 2,000 I.U.…”