{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T05:11:08Z","timestamp":1777957868622,"version":"3.51.4"},"reference-count":23,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T00:00:00Z","timestamp":1777939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:p>\n                    This study aimed to investigate how levels of serum follicle-stimulating hormone (FSH) on Day 7 of ovarian stimulation are related to the number of oocytes retrieved, and identify any cutoff or threshold point in protocols using gonadotropin-releasing hormone (GnRH) antagonists. We examined data from January 2017 to June 2024, covering 9,969 cycles from 7,981 patients using GnRH antagonists as part of\n                    <jats:italic>in vitro<\/jats:italic>\n                    fertilization processes. We found a complex link between serum FSH and oocyte collection. Lower serum FSH on Day 7 was associated with collection of fewer oocytes (\u03b2 = \u22120.531, p &amp;lt; 0.0001), and different levels were associated with changes in the number of oocytes collected. The key point was 9.13mIU\/mL. If serum FSH exceeded 9.13 mIU\/mL on Day 7, each 1mIU\/mL increase reduced the number of oocytes collected by 0.07 (effect \u03b2 = \u22120.07, 95% confidence interval [CI] \u22120.10 to \u22120.05, P &amp;lt; 0.0001). When serum FSH was below 9.13 mIU\/mL, each 1 mIU\/mL rise increased the number of oocytes collected by 1.18 (effect \u03b2 = 1.18, 95% CI 0.95 to 1.41, P &amp;lt; 0.0001). This association suggests that it may be possible to improve ovarian reaction by raising the FSH dose if serum FSH is under 9.13 mIU\/mL. However, if serum FSH is already over 10 mIU\/mL, it seems likely that other steps may be needed to increase ovarian reaction, although these hypotheses will need to be tested in future studies.\n                  <\/jats:p>","DOI":"10.3389\/fendo.2026.1757107","type":"journal-article","created":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T04:16:55Z","timestamp":1777954615000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["High serum FSH levels on day 7 of stimulation are negatively associated with oocyte retrieval in GnRH antagonist protocols: real-world evidence from 9,969 IVF cycles in China"],"prefix":"10.3389","volume":"17","author":[{"given":"Xiu","family":"Luo","sequence":"first","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hong","family":"Ye","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]},{"name":"Key Laboratory of Human Embryo Engineering, Chongqing Maternal and Child Health Care Hospital","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Pei","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yao","family":"He","sequence":"additional","affiliation":[{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fujie","family":"Li","sequence":"additional","affiliation":[{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Han","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shun","family":"Xiong","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shubiao","family":"Han","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jingyu","family":"Li","sequence":"additional","affiliation":[{"name":"Key Laboratory of Human Embryo Engineering, Chongqing Maternal and Child Health Care Hospital","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaodong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Human Embryo Engineering, Chongqing Maternal and Child Health Care Hospital","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guoning","family":"Huang","sequence":"additional","affiliation":[{"name":"Women and Children\u2019s Hospital of Chongqing Medical University","place":["Chongqing, China"]},{"name":"Chongqing Health Center for Women and Children","place":["Chongqing, China"]},{"name":"Key Laboratory of Human Embryo Engineering, Chongqing Maternal and Child Health Care Hospital","place":["Chongqing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2014.08.013","article-title":"Ovarian response to recombinant human follicle-stimulating hormone: a randomized, antim\u00fcllerian hormone-stratified, dose-response trial in women undergoing in vitro fertilization\/intracytoplasmic sperm injection","volume":"102","author":"Arce","year":"2014","journal-title":"Fertil Steril"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2020.10.059","article-title":"Randomized, assessor-blind, antim\u00fcllerian hormone-stratified, dose-response trial in Japanese in vitro fertilization\/intracytoplasmic sperm injection patients undergoing controlled ovarian 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