Moran Shapira

Purpose: Evaluate outcomes of Day-4 embryo transfer according to embryonic developmental stage. Methods: This retrospective single-center study included fresh IVF/ICSI cycles with day-4 single embryo transfer between January 2021 and July 2025. Cycles with double embryo transfer, rescue ICSI, or missing follow-up were excluded. Transfers were divided into three groups based on embryonic stage at transfer: cleavage, morula or blastocyst-stage. Demographic and cycle characteristics, as well as clinical outcomes, were compared. Clinical pregnancy was the primary outcome. Results: A total of 669 day-4 single fresh embryo transfer cycles were included: 130 cleavage-stage (19.4%), 449 morula-stage (67.1%), and 90 blastocyst-stage (13.5%). Compared to the morula stage, the cleavage-stage group was characterized by an older age, lower oocyte yield and fewer 2PN embryos, while the blastocyst-stage group was characterized by a younger age and a similar oocyte yield and 2PN embryos. Clinical pregnancy rates increased significantly with advancing embryonic stage (10.0%, 32.96%, and 48.89%, respectively; p < 0.05). In multivariable analysis, only increasing maternal age (OR 0.92, 95% CI 0.88–0.96) and cleavage-stage transfer (OR 0.37, 95% CI 0.18–0.78) remained negatively associated with clinical pregnancy. Conclusions: Fresh day 4 embryo transfer outcomes are strongly influenced by embryonic developmental stage. Cleavage-stage embryos on day 4 are associated with poor pregnancy rates and may benefit from extended culture. In contrast, day 4 morula or blastocyst transfer represents a viable clinical option, particularly when logistical constraints preclude day 5 transfer.

STUDY QUESTION: Can vitrification with a shortened equilibration solution (ES) be safely applied to human embryos without compromising key embryological clinical outcomes? SUMMARY ANSWER: Vitrification with shortened equilibration was associated with comparable observed survival, developmental progression, and blastocyst re-expansion rates when compared to standard vitrification. WHAT IS KNOWN ALREADY: Vitrification with shortened-equilibration exposure has been primarily evaluated in mouse models and in human oocytes at the germinal vesicle and metaphase II stages, where short exposure times have been shown to maintain post-warming survival and preserve mitochondrial integrity comparable to conventional vitrification. The European Commission (CE) approval exists for the use of shortened-equilibration vitrification protocols in human oocytes, although clinical experience remains limited. Conversely, evidence regarding the application of shortened-equilibration vitrification to human embryos is currently lacking, and there is currently no clinical regulatory approval for embryos or blastocyst vitrification using shortened-equilibration protocols. STUDY DESIGN, SIZE, DURATION: Prospective proof-of-concept study performed in a single IVF laboratory from April 2025 to March 2026. It involved 45 human blastocysts, 49 cleavage-stage embryos, and 102 tripronuclear (3PN) zygotes. Blastocysts were allocated to standard, shortened-equilibration vitrification using full-volume (300 µl) or microdrop loading (50 µl) vitrification. 3PN zygotes were used as a model for early-stage embryo response and were vitrified immediately after fertilization or at the cleavage stage according to group allocation, using standard and shortened-equilibration protocols. PARTICIPANTS/MATERIALS, SETTING, METHODS: All blastocysts were identified as affected by preimplantation genetic testing for monogenic disorders (PGT-M) and used for research only; they were cryopreserved, then warmed using standard protocols, then re-vitrified per group using shortened-equilibration vitrification and subsequently warmed using one-step warming. 3PN zygotes were included as clinically relevant research material and assigned to standard vitrification or shortened-equilibration vitrification (300 µl, 2 min; microdrops 50 µl, 2–3 min). Outcomes included survival rate, day-3 development, blastocyst formation, iDAScore (morphokinetic assessment), and post-warming re-expansion. MAIN RESULTS AND THE ROLE OF CHANCE: 3PN zygotes were allocated to four groups: standard vitrification and shortened-equilibration vitrification using full-volume loading (300 µl, 2-min) or microdrop loading (50 µl, 2 or 3-min). Baseline characteristics were comparable between groups. Post-warming survival rates ranged from 89.2% to 100% (P = 0.408). Day-3 development ranged from 47% to 60% (P = 0.868). Blastocyst formation ranged from 32.0% to 41.2% (P = 0.920). The mean iDAScore ranged from 2.25 to 4.07 (P = 0.281). In cleavage-stage embryos, survival ranged from 78.6% to 95.2% (P = 0.325), and blastocyst formation from 25.0% to 55% (P = 0.262). In blastocysts, survival ranged from 93.3% to 100% (P = 0.592). Re-expansion at 2 h ranged from 82% to 90% after first warming (P = 0.156) and from 82% to 85% after second warming (P = 0.784). Time to complete re-expansion ranged from 3.6 to 4.0 h (P = 0.893). LIMITATIONS, REASONS FOR CAUTION: The sample sizes were limited, and the study may be underpowered to detect differences between groups; patient distribution was unbalanced due to random allocation of samples between groups. In addition, the use of 3PN zygotes limits direct comparison with established blastocyst quality benchmarks due to their inherently reduced developmental potential. WIDER IMPLICATIONS OF THE FINDINGS: Shortened-equilibration vitrification demonstrated comparable post-warming survival, developmental progression, and blastocyst re-expansion to standard vitrification. These findings support the feasibility of shortening equilibration time without compromising key embryological outcomes. If validated in larger studies, this approach may contribute to optimizing and simplifying vitrification protocols in clinical practice. FUNDING: This research received no specific external grant from funding agencies in the public, commercial, or not-for-profit sectors. Departmental and institutional resources from the Infertility and IVF Institute, Sheba Medical Center, supported the study and manuscript preparation. The laboratory also receives general research scholarship support from the Alrov Fund. DISCLOSURES: R.O. reports speaker's fees from Merck Group. The other authors declare that they have no competing interests. TRIAL REGISTRATION NUMBER: N/A

Purpose: To compare the time to initiation of first therapeutic treatment and the outcomes of controlled ovarian stimulation (COS) in breast cancer patients undergoing fertility preservation (FP) in the neoadjuvant chemotherapy (NAC) versus adjuvant chemotherapy (AC) treatment settings. Methods: A retrospective cohort study involving patients with stage 1–3 breast cancer treated with NAC/AC, who underwent FP with random-start COS, between 2015–2023. Baseline, oncologic and COS characteristics and outcomes were collected. Time points related to cancer diagnosis, FP, and first oncologic intervention (surgery or chemotherapy) were calculated. Results: 70 NAC-treated patients were compared to 42 AC-treated patients. Groups were similar in terms of age, marital status, parity and BMI. NAC-treated patients had more advanced disease, more often with lymph node involvement. Median time from diagnosis to FP consult (17 vs 30 days) and to stimulation start (22 vs 59 days) was significantly shorter for NAC-treated patients. Median time from diagnosis to first therapeutic intervention was slightly longer for NAC-treated patients (45 vs 41 days, p < 0.05). Stimulation characteristics were comparable apart from a less frequent use of hCG trigger among NAC-treated patients (4% vs 16%, p < 0.05). First stimulation cycle outcomes such as peak E2 levels, number of retrieved oocytes and fertilization rate were similar, though median number of M2 oocytes was higher in NAC- treated patients (11 vs 8, p < 0.05). Conclusion: Expedited patient care at the neoadjuvant setting led to a statistically significant, yet clinically minimal, delay of cancer therapy. Neither oncologic treatment timelines nor FP outcomes were compromised in the NAC setting.

STUDY QUESTION: What are the outcomes of controlled ovarian stimulation (COS) in childhood cancer survivors (CCS) undergoing fertility preservation (FP) after cancer treatment? SUMMARY ANSWER: CCS who have undergone chemotherapy often show poor outcomes with COS and may need multiple cycles to achieve an adequate number of oocytes for future pregnancy. WHAT IS KNOWN ALREADY: Up to 65% of CCS experience infertility from gonadotoxic treatments. Although it is ideal to consider FP at diagnosis, age and oncological factors often limit this option. After recovery, pubescent survivors, especially those who could not preserve fertility earlier, may be offered oocyte cryopreservation. STUDY DESIGN, SIZE, DURATION: A retrospective study including 20 CCS who underwent COS for oocyte storage between 2015 and 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study involved young CCS who had been previously treated with chemotherapy and were evaluated at an FP center in a tertiary medical center. CCS were encouraged to pursue endocrine surveillance after recovering from cancer and were offered oocyte storage in case diminished ovarian reserve was evident, as dictated by elevated basal FSH (>10 IU/l), decreased anti-Müllerian hormone (AMH; <25th percentile for age), or low antral follicle count (<7). MAIN RESULTS AND THE ROLE OF CHANCE: Mean age at cancer diagnosis was 13.24 ± 5.6 years. Seventeen patients (85%) had been treated with alkylating agents, with five receiving cumulative doses greater than 4000 mg/m2. At the time of FP, a median of 4.25 years after cancer diagnosis, the mean age of patients was 20.6 ± 3.56 years. Mean Day 3 FSH levels were 9.26 ± 3.4 IU/l, and 12 patients had AMH levels below 1 ng/ml. The first stimulation cycle lasted 9.4 ± 2.1 days, with a mean gonadotropin dose of 3246 ± 1057 IU and a median peak estradiol (E2) level of 3733 pmol/ml (IQR 1424–6796). The median number of oocytes retrieved in the first stimulation cycle was 5.5, with a median of four mature oocytes. By the end of the FP process, which involved 1–7 cycles per patient, the median number of oocytes stored was 13.5 (IQR 3.5–18.5). Twelve patients managed to store more than 10 oocytes. LIMITATIONS, REASONS FOR CAUTION: The study is exploratory in its nature, limited by its small sample size and its retrospective design. WIDER IMPLICATIONS OF THE FINDINGS: Oocyte storage is feasible yet limited in young CCS. Despite their young age at the time of FP, CCS who have undergone chemotherapy often show poor outcomes with COS. Ongoing reproductive monitoring after recovery is crucial to identify those who would benefit from FP following cancer treatment. STUDY FUNDING/COMPETING INTEREST(S): The Fertility Preservation Unit funds (Sheba Medical Center) were used to support the authors throughout the study period and manuscript preparation. None of the authors declare any conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Objectives: To determine the rate of pregnancy complications and adverse obstetric and neonatal outcomes of twin pregnancies that were reduced to singleton at an early compared with a later gestational age.Methods: This was a historical cohort study of dichorionic diamniotic twin pregnancies that underwent fetal reduction to singletons in a single tertiary referral center between January 2005 and February 2017. The study population was divided into two groups according to gestational age at fetal reduction: those performed at 11–14 weeks' gestation, mainly at the patient's request or as a result of a complicated medical or obstetric history; and selective reductions performed at 15–23 weeks for structural or genetic anomalies. The main outcome measures compared between pregnancies that underwent early reduction and those that underwent late reduction included rates of pregnancy complications, pregnancy loss, preterm delivery and adverse neonatal outcome.Results: In total, 248 dichorionic diamniotic twin pregnancies were included, of which 172 underwent early reduction and 76 underwent late reduction. Although gestational age at delivery was not significantly different between the late‐ and early‐reduction groups (38 weeks, (interquartile range (IQR), 36–40 weeks) vs 39 weeks (IQR, 38–40 weeks); P = 0.2), the rates of preterm delivery < 37 weeks (28.0% vs 14.0%; P = 0.01), < 34 weeks (12.0% vs 1.8%; P = 0.002) and < 32 weeks (8.0% vs 1.8%; P = 0.026) were significantly higher in pregnancies that underwent late reduction. Regression analysis revealed that late reduction of twins was an independent risk factor for preterm delivery, after adjustment for maternal age, parity, body mass index and the location of the reduced sac. Rates of early complications linked to the reduction procedure itself, such as infection, vaginal bleeding and leakage of fluids, were comparable between the groups (7.0% for early reduction vs 9.2% for late reduction; P = 0.53). There was no significant difference in the rate of pregnancy loss before 24 weeks (0.6% for early reduction vs 1.3% for late reduction; P = 0.52), and no cases of intrauterine fetal death at or after 24 weeks were documented. There was no significant difference in the prevalence of gestational diabetes mellitus, hypertensive disorders of pregnancy, preterm prelabor rupture of membranes or small‐for‐gestational age. The rates of respiratory distress syndrome (6.7% vs 0%; P = 0.002), need for mechanical ventilation (6.7% vs 0.6%; P = 0.01) and composite neonatal morbidity (defined as one or more of respiratory distress syndrome, sepsis, necrotizing enterocolitis, intraventricular hemorrhage, need for respiratory support or neonatal death) (10.7% vs 2.9%; P = 0.025) were higher in the late‐ than in the early‐reduction group. Other neonatal outcomes were comparable between the groups.Conclusions: Compared with late first‐trimester reduction of twins, second‐trimester reduction is associated with an increased rate of prematurity and adverse neonatal outcome, without increasing the rate of procedure‐related complications. Technological advances in sonographic diagnosis and more frequent use of chorionic villus sampling have enabled earlier detection of fetal anatomic and chromosomal abnormalities. Therefore, efforts should be made to complete early fetal assessment to allow reduction during the first trimester. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.