{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T12:37:44Z","timestamp":1777898264120,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2008,12,3]],"date-time":"2008-12-03T00:00:00Z","timestamp":1228262400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2008,12,3]],"date-time":"2008-12-03T00:00:00Z","timestamp":1228262400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Horm Res"],"abstract":"<jats:p>The purpose of this study was to evaluate the influence of the relationship between plasma progesterone (P&lt;sub&gt;4&lt;\/sub&gt;) and estradiol (E&lt;sub&gt;2&lt;\/sub&gt;) levels in the luteal phase for achieving pregnancy in human menopausal gonadotropin (hMG)-human chorionic gonadotropin (hCG)-treated cycles. Plasma P&lt;sub&gt;4&lt;\/sub&gt; and E&lt;sub&gt;2&lt;\/sub&gt; levels were determined in 93 hMG-hCG-treated cycles (23 pregnant and 70 nonpregnant) of 46 patients during 3 periods of the luteal phase, using radioimmunoassay. In addition, 88 spontaneous ovulatory cycles and 100 clomiphene-treated cycles were also studied in the same manner. In hMG-hCG-treated cycles in the early luteal phase, the P&lt;sub&gt;4&lt;\/sub&gt;\/E&lt;sub&gt;2&lt;\/sub&gt; ratio in pregnant cycles was significantly higher than that in nonpregnant cycles. There was no significant difference between the P&lt;sub&gt;4&lt;\/sub&gt;\/E&lt;sub&gt;2 &lt;\/sub&gt;ratios of the luteal phase of hMG-hCG-treated pregnant-group, clomiphene-treated and spontaneous ovulatory cycles. In nonpregnant cycles, however, the P&lt;sub&gt;4&lt;\/sub&gt;\/E&lt;sub&gt;2&lt;\/sub&gt; ratio in hMG-hCG-treated cycles was significantly lower than that in clomiphene-treated or spontaneous ovulatory cycles. These results suggest that in hMG-hCG-treated cycles, the P&lt;sub&gt;4&lt;\/sub&gt;\/E&lt;sub&gt;2&lt;\/sub&gt; ratio may be a more reliable index of luteal function for achieving pregnancy than P&lt;sub&gt;4&lt;\/sub&gt; levels alone.<\/jats:p>","DOI":"10.1159\/000182353","type":"journal-article","created":{"date-parts":[[2008,12,3]],"date-time":"2008-12-03T16:39:41Z","timestamp":1228322381000},"page":"59-63","source":"Crossref","is-referenced-by-count":7,"title":["Influence of Progesterone\/Estradiol Ratio on Luteal Function for Achieving Pregnancy in Gonadotropin Therapy"],"prefix":"10.1159","author":[{"given":"S.","family":"Kamada","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T.","family":"Kubota","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T.","family":"Aso","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2008,12,3]]},"container-title":["Hormone Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000182353","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T09:25:25Z","timestamp":1777627525000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000182353"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,12,3]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000182353","archive":["Portico"],"relation":{},"ISSN":["0301-0163","1423-0046"],"issn-type":[{"value":"0301-0163","type":"print"},{"value":"1423-0046","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,12,3]]}}}