{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T08:18:19Z","timestamp":1762244299267,"version":"build-2065373602"},"reference-count":45,"publisher":"Cambridge University Press (CUP)","issue":"3","license":[{"start":{"date-parts":[[2025,3,21]],"date-time":"2025-03-21T00:00:00Z","timestamp":1742515200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Zygote"],"published-print":{"date-parts":[[2025,6]]},"abstract":"<jats:title>Summary<\/jats:title>\n                  <jats:p>With the advancement in the embryo culture media, which supports nutrient requirements of embryos up to 5 to 6 days, there\u2019s a chance to select more viable embryos, which are more likely to result in pregnancy, compared to earlier stages. Also, there is a controversy regarding the frozen embryo transfer compared to the fresh type. To compare the chemical pregnancy rates between fresh embryo transfer (ET), and frozen embryo transfer (FET), on day 3 (cleavage), and day 4 (morula) of development. In this retrospective study, data of 242 fresh and 758 frozen embryo transfer cycles were obtained in one infertility center in Isfahan, Iran. The study\u2019s groups were assigned based on the day of fresh or frozen embryo transfer (day 3, or day 4 embryos) and the embryo grading. Chemical pregnancy was the main outcome measurement (implantation rates). The chemical pregnancy rate was higher in the good quality frozen embryo day 3 and transfer on day 4 group (40.1%). This rate was near the results of transferring the good quality frozen embryo on day 4 (39.2 %). There was no significant difference in the chemical pregnancy rate related to the number of transferred embryos (p = 0.55). The higher PRs, when the embryos were transferred on day 4, provided further support for the morula stage embryo transfer, possibly because of better synchrony with the endometrium. It is concluded that morula\/compact embryos are good candidates for embryo transfer, which simultaneously reduces the number of transferred embryos.<\/jats:p>","DOI":"10.1017\/s0967199425000048","type":"journal-article","created":{"date-parts":[[2025,3,21]],"date-time":"2025-03-21T05:38:16Z","timestamp":1742535496000},"page":"117-124","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":1,"title":["Chemical pregnancy in fresh and cryopreserved cycles, using day 3 (cleavage stage) and day 4 embryos (morula stage)"],"prefix":"10.1017","volume":"33","author":[{"given":"Zahra","family":"Borzouie","sequence":"first","affiliation":[{"name":"Isfahan University of Medical Sciences"},{"name":"Shahid Behashti Hospital"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akram","family":"Hosseini","sequence":"additional","affiliation":[{"name":"Isfahan University of Medical Sciences"},{"name":"Shahid Behashti Hospital"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peyman","family":"Salehi","sequence":"additional","affiliation":[{"name":"Shahid Behashti Hospital"},{"name":"Milad Hospital"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hatav","family":"Ghasemi Tehrani","sequence":"additional","affiliation":[{"name":"Milad Hospital"},{"name":"Isfahan University of Medical Sciences"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elham","family":"Naghshineh","sequence":"additional","affiliation":[{"name":"Milad Hospital"},{"name":"Isfahan University of Medical Sciences"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aliakbar","family":"Taherian","sequence":"additional","affiliation":[{"name":"Kashan University of Medical Sciences"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1133-5004","authenticated-orcid":false,"given":"Mahboubeh","family":"Vatanparast","sequence":"additional","affiliation":[{"name":"Rafsanjan University of Medical Sciences"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"56","published-online":{"date-parts":[[2025,3,21]]},"reference":[{"key":"S0967199425000048_ref7","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.bpobgyn.2018.07.001","article-title":"Single embryo transfer for all","volume":"53","author":"Cutting","year":"2018","journal-title":"Best Practice and Research Clinical Obstetrics and Gynaecology"},{"key":"S0967199425000048_ref6","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2012.06.017"},{"key":"S0967199425000048_ref8","doi-asserted-by":"publisher","DOI":"10.1093\/hropen\/hoz038"},{"key":"S0967199425000048_ref45","doi-asserted-by":"publisher","DOI":"10.1007\/s00404-018-4786-5"},{"key":"S0967199425000048_ref11","doi-asserted-by":"publisher","DOI":"10.1159\/000323500"},{"key":"S0967199425000048_ref1","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2011.02.001"},{"key":"S0967199425000048_ref26","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2015.06.031"},{"key":"S0967199425000048_ref33","doi-asserted-by":"crossref","first-page":"1890","DOI":"10.1093\/humrep\/deg339","article-title":"Effect of developmental stage of embryo at freezing on pregnancy outcome of frozen\u2013thawed embryo transfer","volume":"18","author":"Salumets","year":"2003","journal-title":"Human Reproduction"},{"key":"S0967199425000048_ref35","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2011.05.050"},{"key":"S0967199425000048_ref43","first-page":"116","article-title":"Development of a dynamic machine learning algorithm to predict clinical pregnancy and live birth rate with embryo morphokinetics","volume":"3","author":"Yang","year":"2022","journal-title":"FandS Reports"},{"key":"S0967199425000048_ref44","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1186\/s12958-021-00824-y","article-title":"Sequential cleavage and blastocyst embryo transfer and IVF outcomes: a systematic review","volume":"19","author":"Zhang","year":"2021","journal-title":"Reproductive Biology and Endocrinology"},{"key":"S0967199425000048_ref12","doi-asserted-by":"crossref","unstructured":"Glujovsky, D. , Retamar, A.M.Q. , Sedo, C.R.A. , Ciapponi, A. , Cornelisse, S. and Blake, D. 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Published by Cambridge University Press","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}}]}}