Reproductive biomedicine online最新文献

{"title":"Outside Back Cover - Editorial Board","authors":"","doi":"10.1016/S1472-6483(26)00233-6","DOIUrl":"10.1016/S1472-6483(26)00233-6","url":null,"abstract":"","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 4","pages":"Article 105692"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147702477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epidemiology of endometriosis based on real-world data in Japan","authors":"Mizuki Ohashi ,&nbsp;Jun Matsubayashi ,&nbsp;Kana Sugeta ,&nbsp;Yuichiro Yano ,&nbsp;Kaori Kitaoka ,&nbsp;Takashi Murakami ,&nbsp;Shunichiro Tsuji","doi":"10.1016/j.rbmo.2025.105379","DOIUrl":"10.1016/j.rbmo.2025.105379","url":null,"abstract":"<div><h3>Research question</h3><div>Considering the progressively delayed age of pregnancy, what is the current epidemiology of endometriosis in Japan, including its prevalence, incidence and medication patterns, as revealed by a large-scale, real-world dataset?</div></div><div><h3>Design</h3><div>A descriptive analysis of a health insurance dataset from January 2005 to July 2023. The study included adolescent girls and women aged 15 years or older with available data and at least 2 years of follow-up data. The main outcome measures were the prevalence of endometriosis, the age-specific incidence and the hypothetical cumulative incidences.</div></div><div><h3>Results</h3><div>Initially, 4,917,037 adolescent girls and women with at least 2 years of follow-up data were identified as potential participants, 285,309 of whom were diagnosed with endometriosis at 15–50 years of age. The prevalence of endometriosis increased consistently from 2006 to 2022, reaching 3.62% in 2022. The highest incidence was observed at 26 years of age. In older groups, the incidence of adenomyosis was higher than that of endometrioma. The hypothetical cumulative incidences were 37.34% for overall endometriosis and 20.08% for endometriosis treated with medications, with increasing trends observed for both conditions.</div></div><div><h3>Conclusions</h3><div>The hypothetical lifetime incidence of endometriosis by age 50 years was approximately one-third among women, and one-fifth required medication for its treatment, highlighting the need for increased awareness and improved management in clinical settings.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 4","pages":"Article 105379"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk of progesterone elevation in patients with low ovarian reserve using long-acting FSH IVF protocol: a randomized controlled trial","authors":"Enrico Papaleo ,&nbsp;Antonio Quartucci ,&nbsp;Mara Zanirato ,&nbsp;Daria Marzanati ,&nbsp;Valeria Stella Vanni ,&nbsp;Edoardo Delfanti ,&nbsp;Giulia Bertapelle ,&nbsp;Massimo Candiani","doi":"10.1016/j.rbmo.2025.105270","DOIUrl":"10.1016/j.rbmo.2025.105270","url":null,"abstract":"<div><h3>Research question</h3><div>Does the long-acting stimulation protocol with corifollitropin alfa (CFA) followed by daily low-dose recombinant FSH (r-FSH) reduce the risk of premature progesterone elevation (PPE) in women with low ovarian reserve compared with daily high-dose r-FSH?</div></div><div><h3>Design</h3><div>This randomized controlled trial, conducted from February 2022 to May 2024, enrolled 110 patients who met the Bologna criteria for poor ovarian responders. Participants were randomized into two groups: the intervention group received long-acting CFA followed by daily 150 IU r-FSH from day 8; and the control group received daily 300 IU r-FSH. The primary outcome was the proportion of patients with progesterone ≥1.1 ng/ml on the day of human chorionic gonadotrophin trigger. Secondary outcomes included number of retrieved oocytes, fertilization rate, fresh embryo transfer rate, and pregnancy rate.</div></div><div><h3>Results</h3><div>A significantly lower rate of PPE was observed in the CFA group compared with the control group [2/56 (3.6%) versus 12/54 (22.2%), respectively]. CFA stimulation was associated with an 89% reduction in the odds of PPE (OR 0.11, 95% CI 0.02–0.55; <em>P</em> = 0.007). Fresh embryo transfer was achieved in 34/52 (65%) patients in the CFA group versus 21/48 (44%) patients in the control group (<em>P</em> = 0.04).</div></div><div><h3>Conclusions</h3><div>Ovarian stimulation with long-acting CFA plus daily 150 IU r-FSH significantly reduced the risk of PPE and increased the feasibility of fresh embryo transfer in patients with low ovarian reserve. This strategy may offer a better approach for managing PPE, and may improve overall IVF success for this specific patient population.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105270"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146119918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative analysis of uterine peristalsis in women with adenomyosis using optical flow for motion quantification","authors":"Sania Latif ,&nbsp;Shaheer U Saeed ,&nbsp;Yipeng Hu ,&nbsp;Lucrezia De Braud ,&nbsp;Ephia Yasmin ,&nbsp;Ertan Saridogan ,&nbsp;Dimitrios Mavrelos","doi":"10.1016/j.rbmo.2025.105073","DOIUrl":"10.1016/j.rbmo.2025.105073","url":null,"abstract":"<div><h3>Research question</h3><div>Do women with adenomyosis have altered uterine peristalsis, and can an objective and reproducible tool be developed to quantify uterine peristalsis on transvaginal sonography (TVS)?</div></div><div><h3>Design</h3><div>Prospective observational cohort study in women with moderate to severe adenomyosis (<em>n</em> = 26) or a normal uterus (<em>n</em> = 40) undergoing TVS during assisted conception. TVS recordings (<em>n</em> = 143) were conducted at baseline, day 6–10 of ovarian stimulation and day of embryo transfer by operator A, and then repeated by operator A, B or C. Image data were stored offline for optical flow analysis. Pixel-level displacements for points at the endometrial–-myometrial junction were used to compute peristalsis frequency and amplitude by fitting to the two-dimensional wave equation. Fit error was taken as a measure of wave coordination. Inter-class correlation coefficient (ICC) was calculated to assess inter- and intra-observer agreement.</div></div><div><h3>Results</h3><div>Women with adenomyosis had a significantly higher fit error at all time points during the IVF cycle (baseline: + 0.725, <em>P</em> &lt; 0.001; ovarian stimulation: + 0.612, <em>P</em> = 0.004; embryo transfer: + 0.627, <em>P</em> &lt; 0.001), indicating lower uterine peristalsis coordination compared with women with a normal uterus. Inter- and intra-observer agreement for each wave feature (frequency, amplitude and coordination of uterine peristalsis and myometrial contractility) was found to be moderate to good (intra-observer ICC: 0.62–0.75, inter-observer ICC: 0.58–0.79).</div></div><div><h3>Conclusion</h3><div>An objective and reproducible measuring tool is proposed to quantify uterine peristalsis using TVS, with potential for wide application across assisted conception and gynaecology settings.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105073"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding uterine contractility: from physiology to pathology, through emerging technologies","authors":"Pierpaolo Nicolì ,&nbsp;Paola Viganò ,&nbsp;Dominique de Ziegler ,&nbsp;Gabriele Saccone ,&nbsp;Stefania Saponara ,&nbsp;Salvatore Giovanni Vitale ,&nbsp;Edoardo Di Naro ,&nbsp;Ettore Cicinelli ,&nbsp;Vincenzo Pinto ,&nbsp;Amerigo Vitagliano","doi":"10.1016/j.rbmo.2025.105355","DOIUrl":"10.1016/j.rbmo.2025.105355","url":null,"abstract":"<div><div>Uterine contractility has emerged as a potential key element in the orchestration of female reproductive functions, with specific motility patterns seemingly aligning with hormonal fluctuations throughout the menstrual cycle. These dynamic contractility profiles appear to facilitate various stages of conception, underscoring the importance of maintaining physiological uterine kinetics for fertility. Altered uterine contractility might thus contribute to cases of unexplained infertility. By offering a comprehensive reappraisal of uterine contractility across both physiological and pathological contexts, this review has been undertaken to challenge conventional fertility paradigms. The review outlines uterine anatomy and details the genesis and regulation of uterine contractions, emphasizing the electrophysiological role of uterine pacemaker cells, namely interstitial Cajal-like cells. It also provides a thorough overview of current methodologies for assessing uterine contractility, focusing on non-invasive ultrasound-based approaches, and discussing both innovative applications of established techniques and entirely novel diagnostic methods. The review then evaluates the various physiological uterine contractility patterns observed across the menstrual cycle, and finally presents evidence supporting potential causal links between impaired uterine contractility and fertility-threatening uterine pathologies. Since the directionality of this association remains uncertain, longitudinal studies are needed to determine whether alterations in uterine contractility precede or are a consequence of uterine disease. This is a distinction with critical implications for both treatment and prevention strategies in reproductive medicine.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105355"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146195588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the reproductive potential of late mature cryopreserved oocytes","authors":"Keri Bergin ,&nbsp;Ashna Mehra ,&nbsp;Rick Slifkin ,&nbsp;Morgan Baird ,&nbsp;Dmitry Gounko ,&nbsp;Carlos Hernandez-Nieto ,&nbsp;Joseph Lee ,&nbsp;Chelsea Canon ,&nbsp;Alan B. Copperman ,&nbsp;Lucky Sekhon","doi":"10.1016/j.rbmo.2025.105231","DOIUrl":"10.1016/j.rbmo.2025.105231","url":null,"abstract":"<div><h3>Research question</h3><div>Are there any differences in the warming, fertilization and embryo development outcomes of late mature cryopreserved oocytes versus immediately mature cryopreserved oocytes?</div></div><div><h3>Design</h3><div>This retrospective cohort study analysed autologous oocyte cryopreservation cycles with warming from January 2016 to September 2024. Group 1 comprised oocytes that were mature [metaphase II (MII)] at retrieval (assessed within 1 h of retrieval), and Group 2 comprised late mature oocytes, which included day 0 and day 1 late mature oocytes, which reached MII on re-assessment after short term (4–6 h) and next-day (18–28 h) rescue in-vitro maturation, respectively. Comparative statistics and univariate analysis were performed using Wilcoxon rank sum test and chi-squared test. Logistic regression fitted with a generalized estimating equation, adjusted for oocyte age, anti-Müllerian hormone, body mass index, year of oocyte cryopreservation and year of oocyte warming, was performed for warming survival, fertilization, blastulation and ploidy rates.</div></div><div><h3>Results</h3><div>Among 565 patients (699 cryopreservation and 629 warming cycles), Group 1 included 6899 oocytes that were mature at retrieval and Group 2 included 956 late mature oocytes. The warming survival rate was comparable between the groups (79.4% versus 78.0% for Groups 1 and 2, respectively; <em>P</em> = 0.33). The fertilization rate was significantly higher in Group 1 (75.3%) than Group 2 (59.8%) (adjusted OR 0.52, 95% CI 0.42–0.63; <em>P</em> &lt; 0.001). Group 1 had significantly higher blastulation (37.7% versus 26.1%; <em>P</em> ≤ 0.001) and euploidy (54.5% versus 39.3%; <em>P</em> = 0.0023) rates compared with Group 2, and this was confirmed on adjusted analysis. A subanalysis showed no difference between day 0 and day 1 late mature oocytes.</div></div><div><h3>Conclusions</h3><div>Late mature cryopreserved oocytes show lower reproductive potential than oocytes that are mature at retrieval. This could be attributed to dysynchronous cytoplasmic and nuclear maturation. Despite suboptimal development, late mature oocytes can create high-quality blastocysts, offering additional opportunities for future family-building.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105231"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146197870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parenthood intentions and fertility knowledge in the Nordic population 1970 to 2021 – a scoping review","authors":"Sára á Lakjuni ,&nbsp;Lone Schmidt ,&nbsp;Søren Ziebe ,&nbsp;Randi Sylvest ,&nbsp;Ditte Vassard ,&nbsp;Gritt Marie Hviid Malling","doi":"10.1016/j.rbmo.2025.105342","DOIUrl":"10.1016/j.rbmo.2025.105342","url":null,"abstract":"<div><div>Fertility rates are decreasing globally, and the Nordic countries currently have fertility rates of 1.3-1.5 per woman. The objectives of this scoping review, covering the Nordic welfare states since 1970, were to explore women’s and men’s parenthood intentions, their assessment of important circumstances for family building and their fertility knowledge. Overall, 24 quantitative studies and 6 qualitative studies were included. Across studies, the majority of both women and men expressed a desire to have children, while 0–14% did not wish to do so. Among those having parenthood intentions approximately 85% wanted to have two or three children. Parenthood intentions did not decline during the 50-year period of the empirical studies. Hence, as fertility rates are substantially decreasing, the gap between parenthood intentions and actual birth rates is widening. Since 2006, 12 of the included studies explored study participants’ fertility knowledge. All studies except one reported uncertain fertility knowledge, either overestimating or underestimating the probability of spontaneous pregnancy, or overestimating the success rate after IVF treatment. There is an urgent need for cross-disciplinary and structural efforts to bridge the increasing gap between desired and actualized parenthood.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105342"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146213683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of endometriosis and adenomyosis on oocyte quality: an evaluation of 205,978 oocytes","authors":"Semra Kahraman,&nbsp;Ipek Duzguner,&nbsp;Yucel Sahin","doi":"10.1016/j.rbmo.2025.105234","DOIUrl":"10.1016/j.rbmo.2025.105234","url":null,"abstract":"<div><h3>Research question</h3><div>Does the presence of endometriosis and/or adenomyosis, adversely affect oocyte morphology?</div></div><div><h3>Design</h3><div>Retrospective, single-centre study evaluating 29,130 ART cycles between August 2011 and March 2023. Patients diagnosed with endometriosis and/or adenomyosis, were included (<em>n</em> = 4602 cycles; 27,204 oocytes). Two pre-defined subgroups were evaluated: adenomyosis with or without endometriosis (<em>n</em> = 497 patients; <em>n</em> = 3377 oocytes); and endometriosis-only patients (endometriosis without adenomyosis) (<em>n</em> = 3355 patients; <em>n</em> = 24,320 oocytes). The control group included all patients without endometriosis or adenomyosis. Oocyte morphology, cycle characteristics, fresh and frozen embryo transfer outcomes were compared between the study and control groups. Oocyte morphology results were reported using effect sizes owing to the large number of oocytes analysed.</div></div><div><h3>Results</h3><div>Phi effect size indicated only negligible differences in oocyte morphology between endometriosis and control groups. In endometriosis cases, a significantly lower number of aspirated, mature and fertilized oocytes were found compared with the control group (<em>P</em> &lt; 0.001, all). Cliff’s delta effect size indicated only negligible differences in oocyte morphology between adenomyosis and endometriosis only groups. No significant difference was found between embryo transfer outcomes. Adenomyosis with or without endometriosis patients had lower pregnancy and live birth rates (<em>P</em> &lt; 0.001, both) and higher biochemical and clinical pregnancy loss rates (<em>P</em> = 0.009 and <em>P</em> = 0.01 respectively) compared with patients with endometriosis only.</div></div><div><h3>Conclusions</h3><div>Endometriosis and adenomyosis did not affect oocyte morphology. Clinical pregnancy and live birth rates were unaffected by endometriosis. Adenomyosis increased the risk of pregnancy loss and decreased live birth rates.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105234"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plastic pollution in human reproduction: should we worry?","authors":"Martina Broggiato ,&nbsp;Stefania Pezzana ,&nbsp;Chiara Scaccabarozzi ,&nbsp;Francesca Parisi ,&nbsp;Claudia Vanetti ,&nbsp;Chiara Katerina Guinea Montalvo ,&nbsp;Valeria M Savasi ,&nbsp;Claudio Fenizia","doi":"10.1016/j.rbmo.2025.105343","DOIUrl":"10.1016/j.rbmo.2025.105343","url":null,"abstract":"<div><div>Micro- and nanoplastics (MNP) are pervasive pollutants, detected in every ecosystem. Human exposure is extensive, and their capacity to cross biological barriers and accumulate in tissues raises growing concerns about reproductive health and pregnancy outcomes. Research has shown the presence of MNP in human placenta, fetal meconium and amniotic fluid, confirming their ability to reach the fetal compartment, potentially increasing risks for fetal development. In women, MNP have also been detected in follicular fluid, although their specific effects remain to be determined. In-vitro studies have reported MNP-induced placental vascular damage, whereas murine models suggest impaired ovarian function, reduced oocyte quality and decreased pregnancy rates after MNP exposure. In men, MNP have been identified in testicular tissue and semen. Animal studies report decreased sperm count and quality, likely because of oxidative stress, hormonal disruption and inflammation. Various techniques are available for detecting MNP in biological tissues. Mass and Raman spectroscopy are among the most widely used, each offering specific advantages and limitations. Interpreting experimental data also requires caution, as many in-vitro and in-vivo models use unrealistically high doses of pristine polymers lacking environmental additives, potentially limiting the relevance of their findings to real-world exposures.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105343"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Day 3 versus Day 5 refreshment of single-step medium for embryos cultured in a benchtop dry incubator: a randomized sibling oocyte study","authors":"Ibrahim Elkhatib ,&nbsp;Aşina Bayram ,&nbsp;Andrea Abdala ,&nbsp;Noreen Hourani ,&nbsp;Virginia Ferracuti ,&nbsp;Samyra Siqueira ,&nbsp;Erkan Kalafat ,&nbsp;Human M. Fatemi ,&nbsp;Daniela Nogueira","doi":"10.1016/j.rbmo.2025.105288","DOIUrl":"10.1016/j.rbmo.2025.105288","url":null,"abstract":"<div><h3>Research question</h3><div>Does refreshment of single-step culture medium on Day 3 impact blastocyst formation and ploidy rates in embryos cultured in benchtop dry incubators?</div></div><div><h3>Design</h3><div>This randomized sibling oocyte study was performed between July 2021 and October 2023 including 177 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A). Following intracytoplasmic sperm injection, 3016 metaphase II (MII) oocytes were randomized equally to two culture conditions: (a) medium refreshment on Day 3 (R-D3) or (b) medium refreshment on Day 5 (R-D5). All embryos were cultured in single-step medium in a benchtop dry incubator. No embryo assessments were performed between fertilization check and Day 5. Post-insemination outcomes and ploidy rates were compared between the groups.</div></div><div><h3>Results</h3><div>Fertilization rates were similar between R-D3 and R-D5 (OR 0.89, 95% CI 0.75–1.07; <em>P</em> = 0.212). No significant differences in total usable blastocysts (OR 0.88, 95% CI 0.75–1.02; <em>P</em> = 0.091), euploid blastocysts (OR 0.95, 95% CI 0.80–1.13; <em>P</em> = 0.561) or mosaic blastocysts (OR 1.06, 95% CI 0.72–1.56; <em>P</em> = 0.771) per inseminated MII oocyte were observed. Similar results were observed per two pronuclei (2PN) embryo. However, R-D5 was associated with lower odds of Day 5 blastulation (OR 0.80, 95% CI 0.66–0.98; <em>P</em> = 0.032) and high-quality blastulation per inseminated MII oocyte (OR 0.82, 95% CI 0.68–0.98; <em>P</em> = 0.027), although this was not significant when analysed per 2PN embryo. Sensitivity analyses did not identify interactions between treatment group and cycle characteristics.</div></div><div><h3>Conclusion</h3><div>Omitting the refreshment of single-step medium on Day 3 does not compromise the viability of euploid embryos to blastocyst stage, but does lead to a slight reduction in the number of morphologically high-quality blastocysts.</div></div>","PeriodicalId":21134,"journal":{"name":"Reproductive biomedicine online","volume":"52 3","pages":"Article 105288"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146213702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}