A study of the use of intermittent serum luteinizing hormone, progesterone and oestradiol measurements for the detection of ovulation.

The value of luteinizing hormone (LH), progesterone (P) and oestradiol (E2) in serum as an index of ovulation and corpus luteum function was studied in blood samples collected at infrequent intervals during the menstrual cycle from 19 healthy Thai women. A serum P level of more than 3 ng/ml was detectable in 70 to 80 per cent samples obtained between days 20 and 25 and a P peak and/or E2 peak (greater than 150 pg/ml) were found at this time in 85 to 94 per cent of the cycles. In not more than 26 per cent of the cycles was an LH peak (greater than 150 ng/ml-LER-907) detected when all results were considered. A significant P and/or E2 peak on day 22 or 23 occurred in more than 78 per cent of 25 to 33 day cycles, whereas, the P and/or E2 peak was detectable in only 50 per cent of the cycles lasting less than 25 or more than 33 days. The postovulatory serum P levels were the ones most consistently raised in patients studied over several consecutive cycles.