STUDY QUESTION:Can measurement of double-stranded sperm DNA fragmentation (dsSDF) via a neutral comet assay predict the probability of live birth following IVF? SUMMARY ANSWER:In a multicentre IVF cohort, dsSDF measured by a neutral comet assay was a strong, independent predictor of live birth. WHAT IS KNOWN ALREADY:While much of the focus has traditionally been on female factors, emerging research highlights sperm DNA fragmentation as a significant contributor to reproductive outcomes. Over the past decade, studies have shown that different types of sperm DNA damage can affect reproduction differently, with single-stranded breaks being closely linked to reduced spontaneous conception rates, while double-stranded breaks are linked to higher miscarriage rates. STUDY DESIGN, SIZE, DURATION:Prospective cohort study including a total of 302 males from three European IVF clinics, over a 3-year study period (March 2021-October 2024), with 126 healthy sperm donors with confirmed live birth serving as controls. PARTICIPANTS/MATERIALS, SETTING, METHODS:dsSDF was quantified with a neutral comet assay, expressed as Average Comet Score (ACS) and Incidence of Damage (IOD). The primary outcome was live birth per initiated cycle. Associations were evaluated using multivariable logistic regression, adjusting for female and male age (and centre in sensitivity analyses). MAIN RESULTS AND THE ROLE OF CHANCE:Across the cohort, 30% of couples achieved a live birth. Higher dsSDF was associated with reduced odds of live birth, and this association remained statistically significant after adjustment for female age, male age, and recruitment site. Both ACS and IOD were independently predictive of live birth in adjusted models. For ACS, each 1-point increase was associated with 16% lower odds of live birth (OR = 0.84, 95% CI 0.72-0.97; P = 0.026). For IOD, each 1-point increase corresponded to 5% lower odds of live birth (OR = 0.95, 95% CI 0.90-0.99; P = 0.025). As expected, female age remained a strong inverse predictor of live birth across models (OR = 0.86, 95% CI 0.78-0.94; P < 0.001). Using a pragmatic threshold of IOD ≥ 6%, couples were identified with approximately half the odds of achieving a live birth compared to those with IOD < 6% at similar female ages (OR = 0.51, 95% CI 0.28-0.94; P = 0.029). The adverse association between dsSDF and live birth was stronger at higher female ages. LIMITATIONS, REASONS FOR CAUTION:This study examined couples undergoing their first or only IVF cycle and did not include couples with repeat IVF failures. Limitations include potential centre-level confounding, which may benefit from mixed-effects modelling. We did not collect or adjust for several cycle-level covariates that influence live birth (e.g. IVF vs ICSI, number of oocytes retrieved, embryo transfer strategy, use of preimplantation genetic testing for aneuploidy, stimulation protocol), so residual confounding is possible. WIDER IMPLICATIONS OF THE FINDINGS:These results support dsSDF as a clinically relevant biomarker that complements conventional semen parameters. STUDY FUNDING/COMPETING INTEREST(S):The study was part-funded using an unrestricted medical educational grant provided by Merck Serono Limited (0111897641) to the Liverpool Women's Hospital. T.C.B.M., S.H.M., and E.B. were funded in part by UKRI SIP FMI and Peace Plus HF-TIC grants with Ulster University. L.R., A.S., M.L., C.J.L., L.P., and T.C.B.M. are employed at Examen Lab LTD. A.J.D. is a recipient of Merck Serono Limited (0111897641) grant to the Liverpool Women's Hospital. P.H. has received unrestricted research grants from Merck and Gedeon Richter Nordics and honoraria for lectures from Merck, Gedeon Richter, and IBSA. The remaining authors have nothing to disclose. TRIAL REGISTRATION NUMBER:N/A.

Introduction: Chronic pelvic pain (CPP) represents a significant health issue among women, profoundly impacting their quality of life. Current treatment modalities primarily include hormonal therapy, analgesics, or surgical interventions, which may have side effects or be unsuitable for women attempting to conceive. The objective of this study is to determine if cannabidiol (CBD) is an acceptable non-hormonal self-management option for women with CPP. Methods: A prospective, cross sectional observational questionnaire study that included 200 women with CPP who attended the gynaecological department at the Liverpool Women's Hospital (LWH), UK, over a six-month period. The main outcomes included acceptability of CBD as a non-hormonal treatment option for CPP, current treatments/self-management strategies utilised, and interest in participation in future trials investigating CBD for CPP management. Results: Sixteen % (n = 32) of the questioned cohort were taking alternative treatments, 16.3 % (n = 26) had tried cannabis (prescribed/illicit), and 21.3 % (n = 34) had tried Hemp/CBD oil as an alternative treatment option. A total of 82.5 % (n =165) of respondents were willing to try CBD; 73.9 % (n =139) oral, 69.7 % (n =131) a skin patch, 72.3 % (n = 136) a balm/gel and 33 % (n = 62) a CBD infused tampon. Most women, 75.5 % (n = 151), revealed their willingness to take part in future trials involving CBD as a treatment option. Conclusion: CPP remains inadequately treated, leading many women to seek alternative therapies. CBD is considered an acceptable option, with a high proportion of surveyed women reporting current or past use to manage their symptoms.

RESEARCH QUESTION:What is the awareness, adoption and comprehension of artificial intelligence (AI) among assisted reproductive technology (ART) laboratory professionals? DESIGN:A cross-sectional survey consisting of 32 questions was conducted among clinical embryologists worldwide using an online questionnaire between 17 July and 31 August 2023. The survey assessed familiarity with AI technology; current knowledge within laboratories; understanding of AI principles and limitations; and views on ethical concerns, job impacts and scientist-patient relationships. RESULTS:In total, there were 702 survey respondents. The results revealed a high degree of awareness of AI concepts. The participants recognized the potential benefits of AI in embryology, but acknowledged known limitations. While open to the adoption of AI, they expressed reservations surrounding ethics, effects on jobs, and maintaining positive patient relationships. The study uncovered differences in embryologists' opinions based on their years of experience. Most embryologists, independent of age, were positive regarding AI, but workplace concerns diminished with age. CONCLUSIONS:ART professionals are broadly receptive to AI, but ethical and practical uncertainties were raised. Further engagement between developers and end-users can align AI innovation with the values and needs of human practitioners.

Objectives: To report on the outcomes and demographics of azoospermic couples undergoing microscopic testicular sperm extraction (micro-TESE) in a large tertiary referral centre. Subjects and methods: A retrospective study of patients undergoing micro-TESE in a tertiary referral centre from March 2015 to August 2019 was undertaken. Histopathology, patient demographics, comorbidities, patient factors and live birth outcomes were evaluated. Results: A total of 102 micro-TESEs were performed with a sperm retrieval rate (SRR) of 30.3%. The successful group had a mean age of 32.7 years and a mean body mass index (BMI) of 26.8 kg/m 2 . Female partners in the successful group had a mean age of 32.2 years. Twenty percent of female partners had infertility factors, 86.7% had no previous pregnancy and 13.3% had a previous miscarriage. The successful group had 15 live births (50%), while 20% had frozen their sperm. 93.3% achieved live birth from single embryo transfer and currently have unutilised embryos in cryostorage to possibly create siblings in the future. Twenty percent had more than one live birth from a single micro-TESE. Sertoli cell-only syndrome (SCOS) was identified in 57.5% of all cases. This was bilateral in 80% of these cases (four cases only sampled unilaterally due to previous orchidectomies). Of the SCOS group, six men went on to have successful sperm extraction (10%). The presence of previous urologic history/surgery increased the risk of azoospermia by 13%. Conclusion: Men with previous urological conditions have an increased risk of azoospermia. SCOS was identified in 57.5% of cases making it the most common histopathological diagnosis in azoospermic men. Based on our cohort, micro-TESE offers potential sperm retrieval in azoospermic men with SCOS. Successful sperm extraction in patients was associated with 50% live births and appeared to be unaffected by the presence of male/female factors. The number of live births could be higher as 20% had frozen their sperm. Concurrent female issues did not appear to affect successful outcome after micro-TESE, although numbers are small. Level of evidence: Not applicable

Introduction Ovarian hyperstimulation syndrome (OHSS) is the most significant short-term complication of pharmacological ovarian stimulation. Symptoms range from mild abdominal discomfort to rare complications such as renal failure, thromboembolism and respiratory distress syndrome.Currently, clinical practice typically involves monitoring the patient until the condition becomes severe, at which point they are admitted to hospital, where drainage of ascitic fluid (paracentesis) may take place. Preliminary studies have indicated that earlier outpatient paracentesis may reduce the progression of OHSS and prevent hospitalisation in women.Methods and analysis This UK, multicentre, pragmatic, two-arm, parallel-group, adaptive (group sequential with one interim analysis), open-label, superiority, confirmatory, group sequential, individually randomised controlled trial, with internal pilot will assess the clinical and cost-effectiveness and safety of outpatient paracentesis versus conservative management (usual care) for moderate or severe OHSS. 224 women from 20 National Health Service and private fertility units will be randomised (1:1) and followed up for up to 13.5 months. The primary outcome is the rate of OHSS related hospital admission of at least 24 hours within 28 days postrandomisation. The primary analysis will be an intention to treat with difference in hospitalisation rates as measure of treatment effect. Secondary outcomes include time to resolution of symptoms, patient satisfaction, adverse events and cost-effectiveness. A qualitative substudy will facilitate the feasibility of recruitment. Participant recruitment commenced in June 2022.Ethics and dissemination London—Southeast Research Ethics Committee approved the protocol (reference: 22/LO/0015). Findings will be submitted to peer-reviewed journals and abstracts to relevant national and international conferences, as well as being disseminated to trial participants and patient groups.Trial registration number ISRCTN71978064.

BackgroundAn increased body mass index (BMI) can lead to subfertility; however, current literature fails to exclude the effect of other confounding medical conditions, raising questions regarding the direct link between increased BMI and fertility outcomes.ObjectivesTo conduct a systematic review and meta-analysis to elucidate the effects of increased BMI on fertility outcomes in females with no other comorbidities.Search strategyA comprehensive search was conducted using EMBASE, MEDLINE and the Cochrane library from January 2000 until July 2023.Data collection and analysisTwo authors independently conducted data extraction and assessed study quality. Odds ratio (OR) (dichotomous data), standardised mean difference (SMD) (continuous data) and 95% CIs were calculated.Main resultsNine eligible studies were identified: one natural conception and eight assisted reproductive technology (ART). Aggregated data revealed women with BMI ≥25 were less likely to attain clinical pregnancy (OR 0.76, 95% CIs 0.62 to 0.93, p=0.007), with BMI ≥30 associated with a further decreased likelihood of clinical pregnancy (OR 0.61, 95% CIs 0.39 to 0.98, p=0.04). Women with raised BMI required longer duration of stimulation (SMD=0.08, 95% CIs 0.00 to 0.16, p=0.04) and obtained reduced oocytes (SMD=−0.11, 95% CIs −0.18 to −0.04, p=0.002).ConclusionsThese data demonstrate an adverse impact of being overweight/obese on ART outcomes in women with no other diagnosed medical comorbidities and highlight the distinct lack of data concerning the effects of isolated obesity on natural conception. Infertility represents an enormous burden for couples and society; it is essential to identify and tackle modifiable risk factors to improve chances of conception.PROSPERO registration numberCRD42022293631.

Ovarian hyperstimulation (OHSS) is an iatrogenic complication, which commonly occurs after controlled ovarian stimulation (COS) in in-vitro fertilization (IVF) cycles. Most patients experience mild to moderate OHSS and can be managed safely in an outpatient setting with regular monitoring from their fertility treatment centre. However, severe OHSS has traditionally been managed on an inpatient basis to ensure regular monitoring and bloods can be performed to ensure there is no deterioration in the patient's condition. The mainstay of treatment remains supportive care even in severe cases of OHSS. This spotlight article aims to show that, with correct patient selection, most patients can be managed safely and effectively in an outpatient setting.

Abstract Study question Will the transcriptional profile of SSEA-1+ endometrial epithelial cells (EECs) explain their functional role, which can be explored in an in vitro endometrial organoid model? Summary answer SSEA-1+ EECs demonstrate differentially expressed genes (DEGs) and associated functional pathways expected from a basal stem/progenitor cell (SPC) population, agreeing with the in vitro experiments. What is known already Endometrial SPCs are postulated to reside in the basalis and to be responsible for the full phenotypic and functional restoration of the endometrial functionalis layer. SSEA-1+ EECs assume the postulated basalis SPC niche. Previous studies demonstrated isolated SSEA-1+ EECs to have a higher capacity to generate organoids in 3D matrix and display growth like that observed after endometrial denudation. They have lower steroid hormone expression and higher telomerase activity with longer telomere lengths, all suggesting a SPC phenotype. SSEA-1+ EECs co-express nuclear SRY-box transcription factor 9 (nSOX9) and nuclear b-catenin, suggesting an activated Wnt pathway. Study design, size, duration Endometrial samples were collected from eight pre-menopausal women attending the Liverpool Women’s Hospital for benign gynaecological procedures, aged 30-47 years. These patients were having regular menstrual cycles and had not been on any hormonal therapy for at least three months prior to enrolment. Three further endometrial samples were obtained for 3D EEC organoid culture studies. Participants/materials, setting, methods Magnetic-activated cell sorting was used to isolate SSEA-1 enriched/depleted EECs from freshly harvested endometrial samples. Microarray analysis was performed using Agilent human arrays. DEGs and pathway enrichment analysis were explored using R-studio and Ingenuity Pathway Analysis (IPA). Internal and external validation used RT-qPCR, dual-immunofluorescence, and comparison against publicly available endometrial single cell spatial transcriptomic data. Human EEC organoids models were employed to assess hormonal regulation of SSEA-1 expression using immunohistochemistry. Main results and the role of chance SSEA-1+ EECs have a distinct transcriptional profile, with 1,059 DEGs compared with SSEA-1- EECs. Pathway analysis highlighted their role in endometrial regeneration, adhesion, remodelling, and neovascularisation, enriching for pathways such as ‘extracellular matrix structural constituent’, ‘epithelial to mesenchymal transition’, ‘angiogenesis’, ‘TNFα signalling via NFKB’ and ‘Notch signalling’. IPA’s biological functions demonstrated their involvement in tissue homeostasis, tumour suppression and their more quiescent SPC phenotype, with activation of ‘organismal death’ and inhibition of ‘cell movement/migration’ and ‘cell movement/migration of tumour cell lines’. The activation of canonical pathways such as ‘PTEN signalling’ and ‘endocannabinoid cancer inhibition’ demonstrated their fine equilibrium to drive proliferation during regeneration, whilst providing protection from hyperplastic/carcinogenic transformation. Ten selected DEGs were internally validated using RT-qPCR, demonstrating concordance. Dual-immunofluorescence of gene products of DEGs MMP7, MMP26, C11orf52 and CD47 confirmed co-localisation alongside SSEA-1 in an external biological cohort of endometrial samples. External in silico validation using the Garcia-Alonso et al endometrial single-cell transcriptomics dataset, mapped significantly upregulated DEGs MMP7 and MMP26 to mainly SOX9+ and SOX9+/LGR5+ EECs. EEC organoids exposed to hormones (including oestradiol) demonstrated an induction of proliferation and higher proportion of organoids expressing SSEA-1 (46.8% vs 67%) simulating endometrial glandular regeneration process. Limitations, reasons for caution Freshly isolated/sorted EECs were obtained from women at different menstrual cycle phases. Our organoid model system only contained EECs without the stromal component, thus, was not suitable to assess progestogenic response of EECs that occur in vivo. Wider implications of the findings This study provides novel information on human SSEA-1+ EECs, suggesting their pivotal role in endometrial regeneration. Since endometrial epithelial SPCs make a vital contribution to endometrial repair and pregnancy establishment, characterising of these cells in health will allow the development of targeted novel therapies on aberrant SPCs within gynaecological disease. Trial registration number Not applicable

STUDY QUESTION: Does endometrial compaction (EC) help predict pregnancy outcomes in those undergoing ART? SUMMARY ANSWER: EC is associated with a significantly higher clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR), but this does not translate to live birth rate (LBR). WHAT IS KNOWN ALREADY: EC describes the progesterone-induced decrease in endometrial thickness, which may be observed following the end of the proliferative phase, prior to embryo transfer. EC is proposed as a non-invasive tool to help predict pregnancy outcome in those undergoing ART, however, published data is conflicting. STUDY DESIGN, SIZE, DURATION: A literature search was carried out by two independent authors using PubMed, Cochrane Library, MEDLINE, Embase, Science Direct, Scopus, and Web of Science from inception of databases to May 2023. All peer-reviewed studies reporting EC and pregnancy outcomes in patients undergoing IVF/ICSI treatment were included. PARTICIPANTS/MATERIALS, SETTING, METHODS: The primary outcome is LBR. Secondary outcomes included other pregnancy metrics (positive pregnancy test (PPT), CPR, OPR, miscarriage rate (MR)) and rate of EC. Comparative meta-analyses comparing EC and no EC were conducted for each outcome using a random-effects model if I2 > 50%. The Mantel-Haenszel method was applied for pooling dichotomous data. Results are presented as odds ratios (OR) with 95% CI. MAIN RESULTS AND THE ROLE OF CHANCE: Out of 4030 screened articles, 21 cohort studies were included in the final analysis (n = 27 857). No significant difference was found between LBR in the EC versus the no EC group (OR 0.95; 95% CI 0.87-1.04). OPR was significantly higher within the EC group (OR 1.61; 95% CI 1.09-2.38), particularly when EC >= 15% compared to no EC (OR 3.52; 95% CI 2.36-5.23). CPR was inconsistently defined across the studies, affecting the findings. When defined as a viable intrauterine pregnancy <12 weeks, the EC group had significantly higher CPR than no EC (OR 1.83; 95% CI 1.15-2.92). No significant differences were found between EC and no EC for PPT (OR 1.54; 95% CI 0.97-2.45) or MR (OR 1.06; 95% CI 0.92-1.56). The pooled weighted incidence of EC across all studies was 32% (95% CI 26-38%). LIMITATIONS, REASONS FOR CAUTION: Heterogeneity due to differences between reported pregnancy outcomes, definition of EC, method of ultrasound, and cycle protocol may account for the lack of translation between CPR/OPR and LBR findings; thus, all pooled data should be viewed with an element of caution. WIDER IMPLICATIONS OF THE FINDINGS: In this dataset, the significantly higher CPR/OPR with EC does not translate to LBR. Although stratification of women according to EC cannot currently be recommended in clinical practice, a large and well-designed clinical trial to rigorously assess EC as a non-invasive predictor of a successful pregnancy is warranted. We urge for consistent outcome reporting to be mandated for ART trials so that data can be pooled, compared, and concluded on. STUDY FUNDING/COMPETING INTEREST(S): H.A. was supported by the Hewitt Fertility Centre. S.G.P. and J.W. were supported by the Liverpool University Hospital NHS Foundation Trust. D.K.H. was supported by a Wellbeing of Women project grant (RG2137) and MRC clinical research training fellowship (MR/V007238/1). N.T. was supported by the National Institute for Health and Care Research. D.K.H. had received honoraria for consultancy for Theramex and has received payment for presentations from Theramex and Gideon Richter. The remaining authors have no conflicts of interest to report.

BACKGROUND AND AIM A change in kinetic activity of spermatozoa called hyperactivation and the acrosome reaction are two interrelated processes of sperm activation observed in vitro. Although studies have investigated hyperactivation, no correlation has been found between individual sperm motility patterns with fertilization outcomes. In this study, we observed individual human sperm trajectories to determine analytical categories based on their dynamics that correlates to fertilization and blastocyst formation outcomes during ICSI. METHODS A set of 1,637 sperm trajectories in PVP during ICSI, acquired using SiD 2.0 software (IVF 2.0 Ltd., UK), was analyzed retrospectively. The first three Fourier coefficients, the peak velocity and the area of the convex hull from each trajectory were obtained to summarize sperm motion dynamics. Clustering analyses such as k-means, Gaussian mixture model (GMM) and spectral clustering were carried out to explore whether spermatozoa paths fall into similar analytical categories i.e clusters. Principal component analysis (PCA) was used to obtain a two-dimensional visualization of the cluster distribution. Findings were assessed according to fertilization and subsequent embryo development. RESULTS All three clustering methods consistently identified three mathematical clusters as the most structurally coherent groupings, with k-means achieving the highest silhouette score of 0.56. One mathematical cluster was predictive of blastocyst formation (65% of embryos with ICM and TE), indicating a significant correlation between extracted trajectory features and blastocyst quality. This association was statistically validated by a chi-squared test, resulting in a p-value of 0.0029, suggesting a strong association between cluster assignment and blastocyst quality. The 2-dimensional PCA further confirmed the clear separation of the clusters. CONCLUSIONS The congruence of sperm clustering methods identified three patterns of sperm grouping. The significant presence of high-quality blastocysts in a specific cluster, may illustrate the potential of using sperm trajectory characteristics as a non-invasive predictive tool of embryonic developmental capacity. These findings pave the way for advanced analytical techniques in reproductive medicine, particularly for improving in vitro fertilization (IVF) outcomes by allowing sperm selection based on quantitative motility patterns. Future studies may seek to identify new features or apply advanced machine learning techniques to improve predictive accuracy.

Research question: Can an artificial intelligence embryo selection assistant predict the incidence of first-trimester spontaneous abortion using static images of IVF embryos? Design: In a blind, retrospective study, a cohort of 172 blastocysts from IVF cases with single embryo transfer and a positive biochemical pregnancy test was ranked retrospectively by the artificial intelligence morphometric algorithm ERICA. Making use of static embryo images from a light microscope, each blastocyst was assigned to one of four possible groups (optimal, good, fair or poor), and linear regression was used to correlate the results with the presence or absence of a normal fetal heart beat as an indicator of ongoing pregnancy or spontaneous abortion, respectively. Additional analyses included modelling for recipient age and chromosomal status established by preimplantation genetic testing for aneuploidy (PGT-A). Results: Embryos classified as optimal/good had a lower incidence of spontaneous abortion (16.1%) compared with embryos classified as fair/poor (25%; OR = 0.46, P = 0.005). The incidence of spontaneous abortion in chromosomally normal embryos (determined by PGT-A) was 13.3% for optimal/good embryos and 20.0% for fair/poor embryos, although the difference was not significant (P = 0.531). There was a significant association between embryo rank and recipient age (P = 0.018), in that the incidence of spontaneous abortion was unexpectedly lower in older recipients (21.3% for age <= 35 years, 17.9% for age 36-38 years, 16.4% for age >= 39 years; OR = 0.354, P = 0.0181). Overall, these results support correlation between risk of

Expanded carrier screening (ECS) is a genetic screening test carried out by analysing a blood sample. This screen can be used to detect whether the individual unknowingly carries gene variants associated with common genetic conditions, such as cystic fibrosis, that may be passed on to their children. It is typically performed in reproductive medicine for those who are considering having a family either naturally or via fertility treatment. Many donor sperm and egg banks, particularly in the USA and Europe, also perform blanket ECS testing on all their prospective sperm and egg donors. ECS is not currently routine practice in the UK, but a growing number of patients are requesting it before treatment. All of us carry gene variants of some sort that may cause autosomal recessive disease in their children if their partner or donor also carry a variant in the same gene. An autosomal recessive disease means two copies of an abnormal gene must be present in order for the disease or trait (such as cystic fibrosis or sickle cell disease) to develop. One copy of the variant means the person is a carrier but does not have the condition. Two copies, i.e. from the mother and father, means the child has a 25% chance of having the genetic disease. Carrying a gene variant does not mean that the individual would necessarily have any symptoms of the disease or any features of the condition. Genetic tests for specific conditions are currently available either before or during pregnancy for prospective parents who have a family or personal history of a genetic condition, or for those from ethnic backgrounds where certain conditions - such as haemoglobinopathies (blood disorders) - are common, prompting referral to a clinical genetics department. Expanded carrier screens may test for more than 100 genetic conditions. The list of conditions screened for is called a panel. Common panels are 250 or 600 genes. Not all expanded carrier screens that are available analyse the same genes. Some may test for genes that do not cause serious disease, or cause diseases that occur in later life; others test for genes that cause severe conditions in childhood. There is no agreement as to which panel of genes should be tested for in an ECS. Understanding the screening that is being offered, and the meaning of any results, is complicated and requires support from appropriately trained professionals to best inform the prospective parent or parents.

Abstract Study question Is it possible to classify sperm morphology as normal or abnormal based on their kinetic characteristics? Summary answer Using different classifiers, it was found that balanced dataset the classification scores of individual sperm morphology can be optimized during their motility just before ICSI What is known already Sperm selection plays a crucial role during ICSI. This selection by the embryologists is accompanied by two factors: motility parameters of the sperm to be injected, as well as the morphology. Motility affects morphological decision-making which may be subjective due to spermatozoa not being in a narrow vertical space in a PVP droplet, i.e. counting chamber. Machine/Deep Learning models -as classifiers- are gaining popularity in IVF as it could minimize subjectivity in gamete selection. SiD software is an algorithm that from a group of spermatozoa characteristics can support the selection of a single sperm during real time ICSI. Study design, size, duration In this prospective study 1699 individual spermatozoa were video-recorded (resolution of 200 X 200 pix.) during sperm selection in a 7%PVP solution. Motility variables (VSL, VCL, LIN, VAP, ALH, WOB, STR, MAD) were obtained from each video using the software SiD. Each sperm was classified as normal or abnormal. Based on motility variables, different classification models were used to make a morphokinetic association of the variables with the classification of each sperm. Participants/materials, setting, methods 1699 individual spermatozoa were classified and labeled by three senior embryologists into two categories: normal or anormal. To belong to any category, at least two embryologists had to agree. A normalization was applied to the motility data obtained with SiD. Machine learning classification models were applied. The three classification models with the best results were selected to optimize the hyper-parameters and improve their performance. Main results and the role of chance A set of motility variables were obtained using the software SiD1 (IVF2.0 Ltd., UK) these were used as features for each of the sperm samples and were tagged either as normal or abnormal having a total of 257 normal samples and 1442 abnormal samples. Different classification algorithms were used to perform sperm classification as normal and abnormal. Then hyperparameter tuning algorithms such as GridSearch were used to compute the optimum values, finding KNN algorithm to achieve the best results to classify normal and abnormal spermatozoa with 80% accuracy. Given the nature of the unbalanced dataset, the F1 score was calculated, achieving 0.77, other algorithms such as Decision-Tree and Random-Forest were used achieving similar results in the F1 score. We will continue growing the dataset until it is balanced and run the same algorithms expecting the performance to improve. Limitations, reasons for caution Each clinic's laboratory setup, including the camera used to record the ICSI procedure, is a clinic-specific configuration. Sperm abnormality detection is sensitive to camera resolution, showing the classifiers are resolution-dependent observers. To replicate these results, it is important to consider the quality of the camera. Wider implications of the findings Using the selected kinematics features, it is possible to classify individual spermatozoa during motility as having normal or abnormal morphology. Results may improve using standard morphological examination of each population and having more normal sperm samples. Trial registration number Not applicable

Abstract Study question Does ovarian follicle size influence ultimate oocyte fate and embryology outcome? Summary answer Per punctured follicle, higher oocyte yield, MII oocytes, 2PN fertilisation, and utilisable blastocyst is observed as follicle increases in size up to threshold of 15.5mm What is known already It is well known that oocyte maturity and probability of successful fertilisation is correlated to the size of follicles where oocyte originated from. However the true cutoff and ideal size at oocyte retrieval remains elusive. Furthermore, there is no conclusive evidence that embryological outcome in terms of blastocyst morphology and utilisation differs in the mid to large ovarian follicular sizes. Study design, size, duration Prospective observational study undertaken in a tertiary fertility referral centre over 10 months. 50 participants recruited and underwent conventional controlled ovarian stimulation as per unit protocol. A total of 288 follicular punctures performed in the study period. Participants/materials, setting, methods 50 oocyte retrieval (OR) procedures were performed. The size of ovarian follicles was individually measured using transvaginal ultrasound. 288 follicular punctures were performed and up to 3 oocytes per patient were collected for the study to be individually cultured to allow for tracking of oocyte and embryo outcomes. Follicular fluid and spent culture media were collected separately for subsequent metabolomics analysis. Follicular sizes were divided into 6 groups ( < =9.5, 10-12.5, 13-15.5, 16-19.5, 20-23.5, > =24). Main results and the role of chance Oocyte fate included 113 mature oocytes, 83 bipronuclear (2PN) oocytes, 7 cleavage stage embryos, and 39 good quality blastocysts suitable for utilisation in fresh or frozen transfer cycles. When compared to overall average per punctured follicle, there is an association of higher oocyte yield, proportion of MII oocytes, 2PN fertilisation, and utilisable blastocyst as follicle size increases. The threshold for a change in fate appears to be when follicle size increases beyond 15.5mm where optimal follicle size may reach plateau. Proportion of good-quality blastocysts appears to be associated with size of follicles at rates as follow- 0% (less than 10mm), 11.1% (10-12.5mm), 13.2% (13-15.5mm), 15.9% (16-19.5mm), 14.5% (20-23.5mm), and 20% (above 24mm). 23 embryos have been utilised to date, yielding a 50% positive pregnancy rate. Of these utilised embryos resulting in a positive pregnancy test, 81.8% of embryos originated from follicles above 15.5mm. Metabolomics analysis for follicular fluid and spent culture media is ongoing. Limitations, reasons for caution The observational nature of the study along with a small sample size are limitations that did not allow clinical significance to be observed. Wider implications of the findings Oocyte retrieved from follicles less than 10mm is futile. There appears to be a plateau in optimal follicle size where no real detriment is demonstrated. This is an important findings to guide stimulation, especially in cases of asynchronous growth where sacrifice in larger follicles is commonly assumed. Trial registration number Not applicable

The selection of the best single blastocyst for transfer is typically based on the assessment of the morphological characteristics of the zona pellucida (ZP), trophectoderm (TE), blastocoel (BC), and inner cell-mass (ICM), using subjective and observer-dependent grading protocols. We propose the first automatic method for segmenting all morphological structures during the different developmental stages of the blastocyst (i.e., expansion, hatching, and hatched). Our database contains 592 original raw images that were augmented to 2132 for training and 55 for validation. The mean Dice similarity coefficient (DSC) was 0.87 for all pixels, and for the BC, BG (background), ICM, TE, and ZP was 0.85, 0.96, 0.54, 0.63, and 0.71, respectively. Additionally, we tested our method against a public repository of 249 images resulting in accuracies of 0.96 and 0.93 and DSC of 0.67 and 0.67 for ICM and TE, respectively. A sensitivity analysis demonstrated that our method is robust, especially for the BC, BG, TE, and ZP. It is concluded that our approach can automatically segment blastocysts from different laboratory settings and developmental phases of the blastocysts, all within a single pipeline. This approach could increase the knowledge base for embryo selection.

Abstract:Embryo implantation is vital for successful conception but remains to be fully understood. Trophoblast invasion is key for implantation, with anchorage and depth of placentation determined by its extent. There is a dearth of synchronous information regarding IVF, implantation site, and trophoblastic thickness (TT). Our aim was to determine whether pregnancy implantation site and TT, had an impact on outcomes of IVF pregnancies. This prospective observational study was undertaken at a tertiary referral UK fertility unit over 14 months, collecting data on implantation site and TT from three-dimensional (3D) images of the uterus following early pregnancy scan. Of the 300 women recruited, 277 (92%) had live births, 20 (7%) miscarried, 2 (0.7%) had stillbirths, and 1 (0.3%) had a termination. Significantly more pregnancies that resulted in miscarriage (7/20, 35%) were located in the lower uterine cavity when compared to ongoing pregnancies (15/277, 5%) (P < 0.01). TT was significantly higher in ongoing pregnancies when compared with those who miscarried (7.2 mm vs 5.5 mm; P < 0.01). Implantation in the lower half of the uterine cavity and decreased TT are significantly associated with an increased rate of miscarriage. Identification of those at risk should prompt increased monitoring with the aim of supporting these pregnancies. Lay summary:Implantation of an embryo in the womb is vital for a successful pregnancy. We wanted to find out whether findings on an ultrasound scan in early pregnancy had an impact on outcomes of IVF pregnancies. Three hundred women were recruited to the study, 277 (92%) had live births and unfortunately 20 (7%) had a miscarriage, 2 (0.7%) had stillbirths, and 1 (0.3%) had a termination. Many more of the pregnancies that miscarried implanted in the lower part of the womb. The thickness of the infiltration of the pregnancy into the womb was significantly higher in the ongoing pregnancies. We concluded that implantation in the lower half of the womb and reduced infiltration of the pregnancy seen on scan are associated with an increased rate of miscarriage. We propose that when we identify those at risk, we should increase monitoring, with the aim of supporting these pregnancies.