{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T11:33:38Z","timestamp":1768217618084,"version":"3.49.0"},"reference-count":27,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,11]],"date-time":"2026-01-11T00:00:00Z","timestamp":1768089600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Dual stimulation starting in the follicular phase allows retrieval of more oocytes than single follicular-phase controlled ovarian stimulation (COS). However, dual stimulation excludes fresh embryo transfer (ET), forcing us to postpone the first ET. If dual stimulation is performed in a reverse way (\u201creverse\u201d-dual stimulation, R-DS), fresh ET can be performed, potentially reducing the time to pregnancy. The aim of the present study is to investigate reproductive outcomes of R-DS compared to two consecutive COS starting in the follicular phase (2FP-COS). Methods: A retrospective study was performed on 146 poor responders matching Bologna criteria, among which 45 underwent R-DS and 101 received 2FP-COS. In the R-DS group, the first COS began 5 days after ovulation and the second 5 days after oocyte retrieval. The primary outcome was the time to pregnancy. Results: In R-DS, stimulation length, retrieved oocytes, and blastocyst formation rate were comparable in the luteal and follicular COS rounds. Circulating progesterone was always &lt;1.0 ng\/mL at ovulation trigger, and fresh ET was performed with a mean endometrial thickness of 9.27 \u00b1 2.28 mm. Comparing R-DS and 2FP-COS, no differences were found in terms of retrieved oocytes and cumulative live birth rate; however, the R-DS group showed significantly shorter time to pregnancy (52.9 \u00b1 11.6 vs. 103.2 \u00b1 23.2 days, p &lt; 0.05). Conclusions: This study suggests that R-DS is not inferior to two consecutive COS starting in the follicular phase in terms of oocytes retrieved and cumulative live birth rate. R-DS allows immediate fresh ET and can significantly shorten the time to pregnancy, a relevant issue for poor responders\u2019 patients.<\/jats:p>","DOI":"10.3390\/jcm15020582","type":"journal-article","created":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T08:20:37Z","timestamp":1768206037000},"page":"582","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["\u201cReverse\u201d Dual Stimulation Has Comparable Efficacy, but Higher Efficiency, than Two Conventional Follicular Phase Stimulations in Poor Responders Undergoing In Vitro Fertilization"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7734-4499","authenticated-orcid":false,"given":"Andrea Roberto","family":"Carosso","sequence":"first","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chiara","family":"Benedetto","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bernadette","family":"Evangelisti","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8809-2293","authenticated-orcid":false,"given":"Marco","family":"Carosso","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5481-982X","authenticated-orcid":false,"given":"Gianvito","family":"Contangelo","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6402-6750","authenticated-orcid":false,"given":"Stefano","family":"Canosa","sequence":"additional","affiliation":[{"name":"IVIRMA, Global Research Alliance, LIVET, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gianluca","family":"Gennarelli","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 1, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5797-3722","authenticated-orcid":false,"given":"Alberto","family":"Revelli","sequence":"additional","affiliation":[{"name":"Division of Gynecology and Obstetrics 2, Department of Surgical Sciences, City of Health and Science, University of Turin, 10126 Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1016\/j.fertnstert.2018.04.039","article-title":"Cumulative live birth rates according to the number of oocytes retrieved after the first ovarian stimulation for in vitro fertilization\/intracytoplasmic sperm injection: A multicenter multinational analysis including ~15,000 women","volume":"110","author":"Polyzos","year":"2018","journal-title":"Fertil. 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