Mitochondrial DNA variants segregate during human preimplantation development into genetically different cell lineages that are maintained postnatally.

Humans present remarkable diversity in their mitochondrial DNA (mtDNA) in terms of variants across individuals as well as across tissues and even cells within one person. We have investigated the timing of the first appearance of this variant-driven mosaicism. For this, we deep-sequenced the mtDNA of 254 oocytes from 85 donors, 158 single blastomeres of 25 day-3 embryos, 17 inner cell mass and trophectoderm samples of 7 day-5 blastocysts, 142 bulk DNA and 68 single cells of different adult tissues. We found that day-3 embryos present blastomeres that carry variants only detected in that cell, showing that mtDNA mosaicism arises very early in human development. We classified the mtDNA variants based on their recurrence or uniqueness across different samples. Recurring variants had higher heteroplasmic loads and more frequently resulted in synonymous changes or were located in non-coding regions than variants unique to one oocyte or single embryonic cell. These differences were maintained through development, suggesting that the mtDNA mosaicism arising in the embryo is maintained into adulthood. We observed a decline in potentially pathogenic variants between day 3 and day 5 of development, suggesting early selection. We propose a model in which closely clustered mitochondria carrying specific mtDNA variants in the ooplasm are asymmetrically distributed throughout the cell divisions of the preimplantation embryo, resulting in the earliest form of mtDNA mosaicism in human development.

Perspectives on sperm donor anonymity: insights from donor-conceived adults in Belgium.

STUDY QUESTION: Are donor-conceived adults in Belgium interested in obtaining donor information, and do these interests vary based on their family backgrounds? SUMMARY ANSWER: Donor-conceived adults express a significant interest in obtaining donor-related information, with the highest interest reported by offspring from heterosexual couples compared to those from lesbian couple-parented or single-parent families. WHAT IS KNOWN ALREADY: In Belgium, sperm donation is mainly anonymous, but the rise of direct-to-consumer genetic testing challenges this anonymity. STUDY DESIGN, SIZE, DURATION: This was a cross-sectional study involving an online nationwide survey conducted from July 2022 to October 2023. Participants, aged 18 years and older and being aware of their anonymous sperm donor-conceived status, were recruited through various channels. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 203 participants were included: 62.6% grew up in heterosexual families with infertile fathers, 26.1% with lesbian couples, 8.4% with single parents, and 3.0% in various or diverse family structures. The survey was available in both French and Dutch and consisted of 43 questions, including a mix of yes/no questions and multiple-choice items. MAIN RESULTS AND THE ROLE OF CHANCE: The average age of disclosure was 16.5 years, with notably later disclosure in heterosexual couple-parented households. A substantial 82.8% of donor-conceived individuals expressed a keen interest in obtaining non-personally identifiable donor information, while 69% were curious about personally identifiable donor data. Furthermore, 61.6% conveyed a desire for personal contact with their donors, and 26.6% advocated for the inclusion of the donor's name on their birth certificates. Participants raised in lesbian two-parent families exhibited the lowest level of interest in donor-related information compared with those raised in other family structures. An overwhelming 90.1% wondered about the possibility of having half-siblings from the same sperm donor. Analysis of survey responses on DNA database registration revealed that 55.2% of donor-conceived offspring were already registered, with 68.8% discovering the same donor offspring and 30.4% successfully locating their donors. Compared to individuals from other family structures, those raised in heterosexual couple-parented households exhibit a less positive attitude toward their conception through anonymous sperm donation. About 61.6% of donor-conceived individuals reported experiencing distinct emotions compared to their peers, while 44.1% encountered psychological difficulties related to anonymous sperm donation, primarily attributed to late disclosure. The majority supported the idea of informing the donor about the number of children he facilitated to conceive. Lastly, the study highlighted that 21.2% of donor-conceived adults considered becoming donors themselves, and 31.3% expressed willingness to use an anonymous donor whenever faced with fertility challenges. LIMITATIONS, REASONS FOR CAUTION: Our sample size may not fully represent all adults conceived through anonymous sperm donation in Belgium. Participation bias may have influenced the results, especially due to the overrepresentation of participants from heterosexual couples. Additionally, an association exists between individuals raised by heterosexual couples and late disclosure, complicating the analysis by introducing a confounding factor. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study contribute to a better understanding of the needs and preferences of donor-conceived adults, with significant potential impact on patient education and healthcare policy. STUDY FUNDING/COMPETING INTEREST(S): Study funding was not obtained for this research. There are no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.

Circadian serum progesterone variations on the day of frozen embryo transfer in artificially prepared cycles.

RESEARCH QUESTION: What is the intra-day variation of serum progesterone related to vaginal progesterone administration on the day of frozen embryo transfer (FET) in an artificial cycle? DESIGN: A prospective cohort study was conducted including 22 patients undergoing a single blastocyst artificial cycle (AC)-FET from August to December 2022. Endometrial preparation was achieved by administering oestradiol valerate (2 mg three times daily) and consecutively micronized vaginal progesterone (MVP; 400 mg twice daily). A blastocyst FET was performed on the 6th day of MVP administration. Serum progesterone concentrations were measured on the day of transfer at 08:00, 12:00, 16:00 and 20:00 hours. The first and last blood samples were collected just before MVP was administered. RESULTS: The mean age and body mass index of the study population were 33.95 ± 3.98 years and 23.10 ± 1.95 kg/m2. The mean P-values at 08:00, 12:00, 16:00 and 20:00 hours were 11.72 ± 4.99, 13.59 ± 6.33, 10.23 ± 3.81 and 9.28 ± 3.09 ng/ml, respectively. A significant decline, of 2.41 ng/ml (95% confidence interval 0.81-4.00), was found between the first and last progesterone measurements. CONCLUSION: A statistically significant intra-day variation of serum progesterone concentrations on the day of FET in artificially prepared cycles was observed. This highlights the importance of a standardized procedure for the timing of progesterone measurement on the day of AC-FET. Of note, the study results are applicable only to women using MVP for luteal phase support; therefore it is necessary to confirm its validity in comparison with the different existing administration routes of progesterone.

Early versus late follicular phase ovarian stimulation: a randomized controlled trial.

RESEARCH QUESTION: Is late follicular phase stimulation as efficient as early follicular phase stimulation in a gonadotrophin-releasing hormone (GnRH) antagonist protocol in oocyte donors in terms of the number of oocytes. DESIGN: In this open label, phase 3, non-inferiority, randomized controlled trial using a two-arm design with a 1:1 allocation ratio, 84 oocyte donors were allocated to the early follicular start group (control group, n = 41) or the late follicular start group (study group, n = 43). In the control group, women followed a fixed GnRH antagonist protocol with recombinant FSH (r-FSH) 225 IU. In the study group, r-FSH 225 IU was initiated in the late follicular phase. The primary outcome was the number of oocytes. The secondary outcomes were the number of mature oocytes, consumption of gonadotrophins and GnRH antagonist, and cost of medication. RESULTS: The number of oocytes did not differ between the control group and the study group (intent-to-treat analysis 15.5 ± 11.0 versus 14.0 ± 10.7, P = 0.52; per-protocol analysis 18.2 ± 9.7 versus 18.8 ± 7.8, P = 0.62). In addition, the number of mature oocytes did not differ between the groups (14.1 ± 8.1 versus 12.7 ± 8.5, P = 0.48). The duration of stimulation was shorter in the control group (10.0 ± 1.4 versus 10.9 ± 1.5 days, P = 0.01). The total amount of r-FSH used was lower in the control group (2240.7 ± 313.9 IU versus 2453.9 ± 330.1 IU, P = 0.008). A GnRH antagonist was used for approximately 6 days in the control group, while a GnRH antagonist was only prescribed for one woman in the study group (6.0 ± 1.4 days versus 0.13±0.7 days, P < 0.001). There was a significant difference in the cost of medication per cycle between the groups (1147.9 ± 182.8€ in control group versus 979.9 ± 129.0€ in study group, P < 0.001). CONCLUSIONS: Late follicular phase stimulation is as efficient as early follicular phase stimulation in terms of the number of oocytes.

IVF with reception of oocytes from partner in lesbian couples: a systematic review and SWOT analysis.

The growing utilization of assisted reproductive technology (ART) by the LGBTQ+ community, especially among lesbian couples, challenges societal norms and promotes inclusivity. The reception of oocytes from partner (ROPA) technique enables both female partners to have a biological connection to their child. A systematic review was conducted of the literature on ROPA IVF to provide the latest data and a SWOT analysis was subsequently performed to understand the strengths, weaknesses, opportunities and threats associated with ROPA IVF. Publications from 2000 to 2023 with relevant keywords were reviewed and 16 records were included. Five studies provided clinical information on couples who used ROPA IVF. ROPA IVF provides a unique opportunity for a biological connection between the child and both female partners and addresses concerns related to oocyte donation and anonymity. Weaknesses include limited cost-effectiveness data and unresolved practical implications. Opportunities lie in involving both partners in parenthood, advancing ART success rates and mitigating risks. Threats encompass increased pregnancy complications, ethical concerns, insufficient safety data, legal or cultural barriers, and emotional stress. In conclusion, ROPA IVF offers a promising solution for lesbian couples seeking to create a family in which both partners want to establish a biological connection with their child.

Optimized sperm selection: a highly efficient device for the isolation of progressive motile sperm with low DNA fragmentation index.

PURPOSE: To identify the sperm preparation procedure that selects the best sperm population for medically assisted reproduction. METHODS: Prospective observational study comparing the effect of four different sperm selection procedures on various semen parameters. Unused raw semen after routine diagnostic analysis was split in four fractions and processed by four different methods: (1) density gradient centrifugation (DGC), (2) sperm wash (SW), (3) DGC followed by magnetic activated cell sorting (MACS), and (4) using a sperm separation device (SSD). Each fraction was analyzed for progressive motility, morphology, acrosome index (AI), and DNA fragmentation index (DFI). RESULTS: With DGC as standard of care in intraclass correlation coefficient analysis, only SSD was in strong disagreement regarding progressive motility and DFI [0.26, 95%CI (- 0.2, 0.58), and 0.17, 95%CI (- 0.19, 0.45), respectively]. When controlling for abstinence duration, DFI was significantly lower after both MACS and SSD compared to DGC [- 0.27%, 95%CI (- 0.47, - 0.06), p = 0.01, and - 0.6%, 95%CI (- 0.80, - 0.41), p < 0.001, respectively]. Further comparisons between SSD and MACS indicate significantly less apoptotic cells [Median (IQR) 4 (5), 95%CI (4.1, - 6.8) vs Median (IQR) 5 (8), 95%CI (4.9, - 9.2), p < 0.001, respectively] and dead cells [Median (IQR) 9.5 (23.3), 95%CI (13.2, - 22.4) vs Median (IQR) 22 (28), 95%CI (23.1, - 36.8), p < 0.001, respectively] in the SSD group. CONCLUSION: The selection of a population of highly motile spermatozoa with less damaged DNA from unprocessed semen is ideally performed with SSD. Question remains whether this method improves the embryological outcomes in the IVF laboratory.

Electronic witnessing in the medically assisted reproduction laboratory: insights and considerations after 10 years of use.

STUDY QUESTION: What have we learnt after 10 years of electronic witnessing? SUMMARY ANSWER: When applied correctly, an electronic witnessing system can replace manual witnessing in the medically assisted reproduction lab to prevent sample mix-up. WHAT IS KNOWN ALREADY: Electronic witnessing systems have been implemented to improve the correct identification, processing, and traceability of biological materials. When non-matching samples are simultaneously present in a single workstation, a mismatch event is generated to prevent sample mix-up. STUDY DESIGN, SIZE, DURATION: This evaluation investigates the mismatch and administrator assign rate over a 10-year period (March 2011-December 2021) with the use of an electronic witnessing system. Radiofrequency identification tags and barcodes were used for patient and sample identification. Since 2011, IVF and ICSI cycles and frozen embryo transfer cycles (FET) were included; IUIs cycles were included since 2013. PARTICIPANTS/MATERIALS, SETTING, METHODS: The total number of tags and witnessing points were recorded. Witnessing points in a particular electronic witnessing system represent all the actions that have been performed from gamete collection through embryo production, to cryopreservation and transfer. Mismatches and administrator assigns were collected and stratified per procedure (sperm preparation, oocyte retrieval, IVF/ICSI, cleavage stage embryo or blastocyst embryo biopsy, vitrification and warming, embryo transfer, medium changeover, and IUI). Critical mismatches (such as mislabelling or non-matching samples within one work area) and critical administrator assigns (such as samples not identified by the electronic witnessing system and unconfirmed witnessing points) were selected. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 109 655 cycles were included: 53 023 IVF/ICSI, 36 347 FET, and 20 285 IUI cycles. The 724 096 used tags, led to a total of 849 650 witnessing points. The overall mismatch rate was 0.251% (2132/849 650) per witnessing point and 1.944% per cycle. In total, 144 critical mismatches occurred over the different procedures. The yearly mean critical mismatch rate was 0.017 ± 0.007% per witnessing point and 0.129 ± 0.052% per cycle. The overall administrator assign rate was 0.111% (940/849 650) per witnessing point and 0.857% per cycle, including 320 critical administrator assigns. The yearly mean critical administrator assign rate was 0.039 ± 0.010% per witnessing point and 0.301 ± 0.069% per cycle. Overall mismatch and administrator assign rates remained fairly stable during the evaluated time period. Sperm preparation and IVF/ICSI were the procedures most prone to critical mismatch and administrator assigns. LIMITATIONS, REASONS FOR CAUTION: The procedures and methods of integration of an electronic witnessing system may vary from one laboratory to another and result in differences in the potential risks related to sample identification. Individual embryos cannot (yet) be identified by such a system; this makes extra manual witnessing indispensable at certain critical steps where potential errors are not recorded. The electronic witnessing system still needs to be used in combination with manual labelling of both the bottom and lid of dishes and tubes to guarantee correct assignment in case of malfunction or incorrect use of radiofrequency identification tags. WIDER IMPLICATIONS OF THE FINDINGS: Electronic witnessing is considered to be the ultimate tool to safeguard correct identification of gametes and embryos. But this is only possible when used correctly, and proper training and attention of the staff is required. It may also induce new risks, i.e. blind witnessing of samples by the operator. STUDY FUNDING/COMPETING INTEREST(S): No funding was either sought or obtained for this study. J.S. presents webinars on RIW for CooperSurgical. The remaining authors have nothing to declare. TRIAL REGISTRATION NUMBER: N/A.

Lineage segregation in human pre-implantation embryos is specified by YAP1 and TEAD1.

STUDY QUESTION: Which processes and transcription factors specify the first and second lineage segregation events during human preimplantation development? SUMMARY ANSWER: Differentiation into trophectoderm (TE) cells can be initiated independently of polarity; moreover, TEAD1 and YAP1 co-localize in (precursor) TE and primitive endoderm (PrE) cells, suggesting a role in both the first and the second lineage segregation events. WHAT IS KNOWN ALREADY: We know that polarity, YAP1/GATA3 signalling and phospholipase C signalling play a key role in TE initiation in compacted human embryos, however, little is known about the TEAD family of transcription factors that become activated by YAP1 and, especially, whether they play a role during epiblast (EPI) and PrE formation. In mouse embryos, polarized outer cells show nuclear TEAD4/YAP1 activity that upregulates Cdx2 and Gata3 expression while inner cells exclude YAP1 which upregulates Sox2 expression. The second lineage segregation event in mouse embryos is orchestrated by FGF4/FGFR2 signalling which could not be confirmed in human embryos; TEAD1/YAP1 signalling also plays a role during the establishment of mouse EPI cells. STUDY DESIGN, SIZE, DURATION: Based on morphology, we set up a development timeline of 188 human preimplantation embryos between Day 4 and 6 post-fertilization (dpf). The compaction process was divided into three subgroups: embryos at the start (C0), during (C1), and at the end (C2) of, compaction. Inner cells were identified as cells that were entirely separated from the perivitelline space and enclosed by cellular contacts on all sides. The blastulation process was divided into six subgroups, starting with early blastocysts with sickle-cell shaped outer cells (B0) and further on, blastocysts with a cavity (B1). Full blastocysts (B2) showed a visible ICM and outer cells referred to as TE. Further expanded blastocysts (B3) had accumulated fluid and started to expand due to TE cell proliferation and zona pellucida (ZP) thinning. The blastocysts then significantly expanded further (B4) and started to hatch out of the ZP (B5) until they were fully hatched (B6). PARTICIPANTS/MATERIALS, SETTING, METHODS: After informed consent and the expiration of the 5-year cryopreservation duration, 188 vitrified high quality eight-cell stage human embryos (3 dpf) were warmed and cultured until the required stages were reached. We also cultured 14 embryos that were created for research until the four- and eight-cell stage. The embryos were scored according to their developmental stage (C0-B6) displaying morphological key differences, rather than defining them according to their chronological age. They were fixed and immunostained for different combinations of cytoskeleton (F-actin), polarization (p-ERM), TE (GATA3), EPI (NANOG), PrE (GATA4 and SOX17), and members of the Hippo signalling pathway (YAP1, TEAD1 and TEAD4). We choose these markers based on previous observations in mouse embryos and single cell RNA-sequencing data of human embryos. After confocal imaging (LSM800, Zeiss), we analysed cell numbers within each lineage, different co-localization patterns and nuclear enrichment. MAIN RESULTS AND THE ROLE OF CHANCE: We found that in human preimplantation embryos compaction is a heterogeneous process that takes place between the eight-cell to the 16-cell stages. Inner and outer cells are established at the end of the compaction process (C2) when the embryos contain up to six inner cells. Full apical p-ERM polarity is present in all outer cells of compacted C2 embryos. Co-localization of p-ERM and F-actin increases steadily from 42.2% to 100% of the outer cells, between C2 and B1 stages, while p-ERM polarizes before F-actin (P < 0.00001). Next, we sought to determine which factors specify the first lineage segregation event. We found that 19.5% of the nuclei stain positive for YAP1 at the start of compaction (C0) which increases to 56.1% during compaction (C1). At the C2 stage, 84.6% of polarized outer cells display high levels of nuclear YAP1 while it is absent in 75% of non-polarized inner cells. In general, throughout the B0-B3 blastocyst stages, polarized outer/TE cells are mainly positive for YAP1 and non-polarized inner/ICM cells are negative for YAP1. From the C1 stage onwards, before polarity is established, the TE marker GATA3 is detectable in YAP1 positive cells (11.6%), indicating that differentiation into TE cells can be initiated independently of polarity. Co-localization of YAP1 and GATA3 increases steadily in outer/TE cells (21.8% in C2 up to 97.3% in B3). Transcription factor TEAD4 is ubiquitously present throughout preimplantation development from the compacted stage onwards (C2-B6). TEAD1 displays a distinct pattern that coincides with YAP1/GATA3 co-localization in the outer cells. Most outer/TE cells throughout the B0-B3 blastocyst stages are positive for TEAD1 and YAP1. However, TEAD1 proteins are also detected in most nuclei of the inner/ICM cells of the blastocysts from cavitation onwards, but at visibly lower levels as compared to that in TE cells. In the ICM of B3 blastocysts, we found one main population of cells with NANOG+/SOX17-/GATA4- nuclei (89.1%), but exceptionally we found NANOG+/SOX17+/GATA4+ cells (0.8%). In seven out of nine B3 blastocysts, nuclear NANOG was found in all the ICM cells, supporting the previously reported hypothesis that PrE cells arise from EPI cells. Finally, to determine which factors specify the second lineage segregation event, we co-stained for TEAD1, YAP1, and GATA4. We identified two main ICM cell populations in B4-6 blastocysts: the EPI (negative for the three markers, 46.5%) and the PrE (positive for the three markers, 28.1%) cells. We conclude that TEAD1 and YAP1 co-localise in (precursor) TE and PrE cells, indicating that TEAD1/YAP1 signalling plays a role in the first and the second lineage segregation events. LIMITATIONS, REASONS FOR CAUTION: In this descriptive study, we did not perform functional studies to investigate the role of TEAD1/YAP1 signalling during the first and second lineage segregation events. WIDER IMPLICATIONS OF THE FINDINGS: Our detailed roadmap on polarization, compaction, position and lineage segregation events during human preimplantation development paves the way for further functional studies. Understanding the gene regulatory networks and signalling pathways involved in early embryogenesis could ultimately provide insights into why embryonic development is sometimes impaired and facilitate the establishment of guidelines for good practice in the IVF lab. STUDY FUNDING/COMPETING INTERESTS: This work was financially supported by Wetenschappelijk Fonds Willy Gepts (WFWG) of the University Hospital UZ Brussel (WFWG142) and the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO, G034514N). M.R. is doctoral fellow at the FWO. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Clinical pregnancy rate for frozen embryo transfer with HRT: a randomized controlled pilot study comparing 1 week versus 2 weeks of oestradiol priming.

RESEARCH QUESTION: Does a frozen-embryo transfer in an artificially-prepared endometrium (FET-HRT) cycle yield similar clinical pregnancy rate with 7 days of oestrogen priming compared to 14 days? DESIGN: This is a single-centre, randomized, controlled, open-label pilot study. All FET-HRT cycles were performed in a tertiary centre between October 2018 and January 2021. Overall, 160 patients were randomized, with a 1:1 allocation, into two groups of 80 patients each: group A (7 days of E2 prior to P4 supplementation) and group B (14 days of E2 prior to P4 supplementation). Both groups received single blastocyst stage embryos on the 6th day of vaginal P4 administration. The primary outcome was the feasibility of such strategy assessed as clinical pregnancy rate, secondary outcomes were biochemical pregnancy rate, miscarriage rate, live birth rate and serum hormone levels on the day of FET. Chemical pregnancy was assessed by an hCG blood test 12 days after FET and clinical pregnancy was confirmed by transvaginal ultrasound at 7 weeks. RESULTS: The analysis included 160 patients who were randomly assigned to either group A or group B on the seventh day of their FET-HRT cycle if the measured endometrial thickness was above 6.5 mm. Following screening failures and of drop-outs, 144 patients were finally included both in group A (75 patients) or group B (69 patients). Demographic characteristics for both groups were comparable. The biochemical pregnancy rate was 42.5% and 48.8% for group A and group B, respectively (p 0.526). Regarding the clinical pregnancy rate at 7 weeks, no statistical difference was observed (36.3% vs 46.3% for group A and group B, respectively, p = 0.261). The secondary outcomes of the study (biochemical pregnancy, miscarriage, and live birth rate) were comparable between the two groups for IIT analysis, as well as the P4 values on the day of FET. CONCLUSIONS: In a frozen embryo transfer cycle, performed with artificial preparation of the endometrium, 7 versus 14 days of oestrogen priming are comparable, in terms of clinical pregnancy rate; the advantages of a seven-day protocol include the shorter time to pregnancy, reduced exposure to oestrogens, and more flexibility of scheduling and programming, and less probability to recruit a follicle and have a spontaneous LH surge. It is important to keep in mind that this study was designed as a pilot trial with a limited study population as such it was underpowered to determine the superiority of an intervention over another; larger-scale RCTs are warranted to confirm our preliminary results. TRIAL REGISTRATION: Clinical trial number: NCT03930706.

Individualized luteal phase support using additional oral dydrogesterone in artificially prepared frozen embryo transfer cycles: is it beneficial?

RESEARCH QUESTION: Does additional supplementation with oral dydrogesterone improve reproductive outcomes in patients with low serum progesterone concentrations on the day of frozen embryo transfer (FET) after artificial (HRT) endometrial preparation? DESIGN: Retrospective, single-centre cohort study including 694 unique patients performing single blastocyst transfer in an HRT cycle. For luteal phase support, intravaginal micronized vaginal progesterone (MVP, 400 mg twice daily) was administered. Serum progesterone concentrations were assessed prior to FET and outco-mes were compared among patients with normal serum progesterone (≥8.8 ng/ml) continuing the routine protocol and patients with low serum progesterone (<8.8 ng/ml) who received additional oral dydrogesterone supplementation (10 mg three times daily) from the day after FET onwards. Primary outcome was live birth rate (LBR), with a multivariate regression model correcting for relevant confounders. RESULTS: Normal serum progesterone concentrations were observed in 547/694 (78.8%) of patients who continued only MVP as planned, whereas low (<8.8 ng/ml) serum progesterone concentrations were detected in 147/694 (21.2%) patients who received additional oral dydrogesterone supplementation on top of MVP from the day after FET onwards. LBR was comparable between both groups: 37.8% for MVP-only versus 38.8% for MVP+OD (P = 0.84). The multivariate logistic regression model indicated that LBR was not significantly associated with the investigated approaches (adjusted odds ratio 1.01, 95% confidence interval 0.69-1.47, P = 0.97). CONCLUSIONS: The current findings suggest that additional oral dydrogesterone supplementation in patients with low serum progesterone concentrations at the moment of transfer could have the potential to rescue reproductive outcomes in HRT-FET cycles. This field of research, however, remains hampered by the absence of randomized controlled trials.

Association between sequence variants in the FSHR gene and reproductive outcomes following IVF in predicted normoresponders.

RESEARCH QUESTION: Is there an association between FSHR sequence variants and reproductive outcomes following IVF in predicted normoresponders? DESIGN: Multicentre prospective cohort study conducted from November 2016 to June 2019 in Vietnam, Belgium and Spain including patients aged <38 years, and undergoing IVF with a predicted normal response with fixed-dose 150 IU rFSH in an antagonist protocol. Genotyping was performed for three FSHR (c.919A>G, c.2039A>G, c.-29G>A) and one FSHB sequence variants (c.-211G>T). Clinical pregnancy rate (CPR), live birth rate (LBR) and miscarriage rate in the first embryo transfer and cumulative live birth rate (CLBR) were compared between the different genotypes. RESULTS: A total of 351 patients underwent at least one embryo transfer. Genetic model analysis that adjusted for patient age, body mass index, ethnicity, type of embryo transfer, embryo stage and number of top-quality embryos transferred revealed a higher CPR for homozygous patients for the variant allele G of c.919A>G when compared to patients with genotype AA (60.3% versus 46.3%, adjusted odds ratio [ORadj] 1.96, 95% confidence interval [CI] 1.09-3.53). Also, c.919A>G genotypes AG and GG presented a higher CPR and LBR when compared with genotype AA (59.1% versus 46.3%, ORadj 1.80, 95% CI 1.08-3.00, and 51.3% versus 39.0%, ORadj 1.69, 95% CI 1.01-2.80, respectively). Cox regression models revealed a statistically significantly lower CLBR for c.2039A>G genotype GG in the codominant model (hazard ratio [HR] 0.66, 95% CI 0.43-0.99). CONCLUSION: These results demonstrate a previously unreported association between variant c.919A>G genotype GG and higher CPR and LBR in infertile patients and reinforce a potential role for genetic background in predicting the reproductive prognosis following IVF.

Intratesticular xenografting of Klinefelter pre-pubertal testis tissue as potential model to study testicular fibrosis.

RESEARCH QUESTION: Is intratesticular xenotransplantation a potential ex-vivo model for studying testicular fibrosis related to Klinefelter syndrome? STUDY DESIGN: First, a feasibility study of an ex-vivo model to study testicular fibrosis in patients with Klinefelter syndrome was performed. Testis tissue from boys with pre-pubertal Klinefelter syndrome (n = 3) and controls (n = 2) (<18 years) was grafted to the mouse testis (n = 12) and recovered after 2, 4, 6 and 8 weeks. Part two of this study consisted of a validation of this model, evaluating the effects of the mast cell blocker ketotifen on the histology of the grafts of Klinefelter syndrome (n = 5) and controls (n = 3), transplanted to mice (n = 10), after 4 weeks of ketotifen or saline treatment. Immunohistochemistry determined the histology of the grafts and the presence of mast cells and spermatogonia. RESULTS: The feasibility study showed that 4 weeks after transplantation, all Klinefelter syndrome grafts could be recovered. Later, degeneration was observed. Most recovered grafts showed an intact histology, with 67 ± 12% intact tubules for the Klinefelter syndrome grafts and 65 ± 15% of intact tubules for the control grafts. In the few remaining Klinefelter syndrome grafts, treatment with ketotifen improved testicular histology compared with non-treated grafts. Graft survival was patient dependent. No germ cell loss was observed after transplantation. CONCLUSION: Xenografting could become a model for the longitudinal study of the fibrotic process related to Klinefelter syndrome; however, the current model has a limited survival period and patient-specific differences in histology.

Cumulative live birth rate after ovarian stimulation with freeze-all in women with polycystic ovaries: does the polycystic ovary syndrome phenotype have an impact?

RESEARCH QUESTION: Do cumulative live birth rates (CLBR) differ between polycystic ovary syndrome (PCOS) phenotypes when a freeze-all strategy is used to prevent OHSS after ovarian stimulation? DESIGN: A single-centre, retrospective cohort study of 422 women with PCOS or polycystic ovarian morphology (PCOM), in whom a freeze-all strategy was applied after GnRH agonist triggering because of hyper-response in their first or second IVF/ICSI. Primary outcome was CLBR; multivariate logistic regression analysis was used. RESULTS: Phenotype A (hyperandrogenism + ovulation disorder + PCOM [HOP]) (n = 91/422 [21.6%]); phenotype C (hyperandrogenism + PCOM [HP]) (33/422 [7.8%]; phenotype D (ovulation disorder + PCOM [OP]) (n = 161/422 [38.2%]); and PCOM (n = 137/422 [32.5%]. Unadjusted CLBR was similar among the groups (69.2%, 69.7%, 79.5% and 67.9%, respectively; P = 0.11). According to multivariate logistic regression analysis, the phenotype did not affect CLBR (OR 0.72, CI 0.24 to 2.14 [phenotype C]; OR 1.55, CI 0.71 to 3.36 [phenotype D]; OR 0.84, CI 0.39 to 1.83 [PCOM]; P = 0.2, with phenotype A as reference). CONCLUSIONS: In women with PCOS, hyper-response after ovarian stimulation confers CLBR of around 70%, irrespective of phenotype, when a freeze-all strategy is used. This contrasts with unfavourable clinical outcomes in women with hyperandrogenism and women with PCOS who underwent mild ovarian stimulation targeting normal ovarian response and fresh embryo transfer. The results should be interpreted with caution because the study is retrospective and cannot be generalized to all cycles as they pertain to those in which hyper-response is observed.

Artificially prepared vitrified-warmed embryo transfer cycles are associated with an increased risk of pre-eclampsia.

RESEARCH QUESTION: What is the association between the development of pre-eclampsia and endometrial preparation prior to vitrified-warmed embryo transfer (frozen embryo transfer, FET)? DESIGN: A retrospective cohort study at a tertiary university-based hospital, including a total of 536 pregnant patients who underwent a FET between 2010 and 2019 and delivered in the same institution; 325 patients underwent natural cycle FET (NC-FET) and 211 artificial cycle FET (AC-FET). RESULTS: Unadjusted, the incidence of pre-eclampsia was significantly higher in AC-FET cycles than in NC-FET cycles (3.7% versus 11.8%, P < 0.001). Multivariable logistic regression analysis showed that, when adjusting for type of endometrial preparation (artificial cycle versus natural cycle), oocyte recipient cycles and African ethnicity, the risk of developing pre-eclampsia was significantly associated with artificial endometrial preparation or oocyte recipient cycles (AC-FET versus NC-FET: odds ratio 2.9, 95% confidence interval 1.4-6.0, P = 0.005). CONCLUSIONS: The current data show a higher incidence of pre-eclampsia in AC-FET versus NC-FET cycles, adding further strength to the existing data on this topic. Together, these recent findings may result in a change in clinical practice, towards a preference for NC-FET cycles over AC-FET cycles in ovulatory patients. Screening for high-risk patients and the development of strategies to mitigate their risk profile could reduce the risk of pre-eclampsia. Further understanding of the different vasoactive substances excreted by the corpus luteum is vital.

Ultrasonographic appearance of the endometrium after saline infusion in women presenting with PRM-associated endometrial changes, due to the use of ulipristal acetate.

Ulipristal acetate (UPA), used for the treatment in women with symptomatic fibroids, is associated with endometrial changes visualised on ultrasound as thickening up to more than 16 mm in approximately 10% of the patients. Is saline infusion sonography (SIS) a good alternative for more invasive techniques, to evaluate the presence of intrauterine pathology? Ten patients, presenting with UPA associated endometrial changes at their follow up ultra-sonographic evaluation, were included. Our study demonstrated that SIS is feasible and painless in patients presenting with UPA associated endometrial changes. The thickened endometrium appears to divide at the midline, making it possible to study both layers separately and exclude any suspected intrauterine pathology. Our findings suggest that SIS may be a first choice, non-invasive, painless technique to provide a proper visualisation to rule out intrauterine pathology when UPA associated endometrial changes are diagnosed after fibroid treatment. This is especially of clinical interest in front of assisted reproductive technology treatment. Invasive techniques can be withheld for patients in whom SIS examination is not contributive.Impact StatementWhat is already known on this subject? Reversible endometrial changes after ulipristal acetate (UPA) treatment in patients with symptomatic fibroids have been described. In patients who receive UPA, especially if planned to undergo ART, assessment of potential endometrial pathology is important as such interfere with proper implantation after ART. Consequently, clinicians may consider ruling out intrauterine pathology by invasive examinations such as biopsy or hysteroscopy after visualisation of the thickened endometrium.What do the results of this study add? Saline infusion sonography (SIS) was feasible and painless in patients presenting with UPA associated endometrial changes.What are the implications of these findings for clinical practice and/or further research? SIS may be a first choice, non-invasive, painless technique to provide a proper visualisation to rule out intrauterine pathology when UPA associated endometrial changes are diagnosed after fibroid treatment. This is especially of clinical interest in front of assisted reproductive technology treatment. Invasive techniques can be withheld for patients in whom SIS examination is not contributive in excluding intrauterine pathology.

Fertility preservation for male patients with childhood, adolescent, and young adult cancer: recommendations from the PanCareLIFE Consortium and the International Late Effects of Childhood Cancer Guideline Harmonization Group.

Male patients with childhood, adolescent, and young adult cancer are at an increased risk for infertility if their treatment adversely affects reproductive organ function. Future fertility is a primary concern of patients and their families. Variations in clinical practice are barriers to the timely implementation of interventions that preserve fertility. As part of the PanCareLIFE Consortium, in collaboration with the International Late Effects of Childhood Cancer Guideline Harmonization Group, we reviewed the current literature and developed a clinical practice guideline for fertility preservation in male patients who are diagnosed with childhood, adolescent, and young adult cancer at age 25 years or younger, including guidance on risk assessment and available methods for fertility preservation. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to grade the available evidence and to form the recommendations. Recognising the need for global consensus, this clinical practice guideline used existing evidence and international expertise to rigorously develop transparent recommendations that are easy to use to facilitate the care of male patients with childhood, adolescent, and young adult cancer who are at high risk of fertility impairment and to enhance their quality of life.

Follitropin alpha versus beta in a first GnRH antagonist ICSI cycle: a retrospective cohort study.

RESEARCH QUESTION: Are cumulative live birth rates (CLBR) after follitropin alpha (Ovaleap®) and follitropin beta (Puregon®) similar when used for ovarian stimulation with ICSI (intracytoplasmic sperm injection) in a first-rank gonadotrophin-releasing hormone (GnRH) antagonist protocol? DESIGN: Retrospective single-centre cohort study including 832 infertile patients undergoing ovarian stimulation with a daily dose of 150-225 IU FSH in their first ICSI cycle at a tertiary referral centre between July 2016 and July 2019. Of those, 349 patients used Ovaleap and 483 patients received Puregon. RESULTS: Baseline characteristics were not statistically different between the groups. The duration of stimulation was slightly longer in the Ovaleap group (10.6 ± 1.7 versus 10.3 ± 1.6 days; P = 0.012). The number of mature oocytes was not statistically different and there was no significant difference in fertilization rate or embryo utilization rate between the two groups. After fresh embryo transfer, biochemical pregnancy rate (137/349 [39.3%] versus 186/483 [38.5%]) as well as clinical pregnancy rate (105/349 [30.1%] versus 152/483 [31.5%]) were comparable (P = 0.83 and 0.67, respectively). Live birth rate (LBR) after fresh embryo transfer (94/349 [26.9%] versus 141/483 [29.2%]; P = 0.48) and CLBR (199/349 [57.0%] versus 287/483 [59.4%]; P = 0.49) were not significantly different. Multivariable regression analysis revealed that the type of gonadotrophin was not associated with CLBR (P = 0.28). CONCLUSION: This retrospective study shows no significant difference in CLBR between Ovaleap and Puregon in patients undergoing their first GnRH antagonist ICSI cycle.

IVF in women aged 43 years and older: a 20-year experience.

RESEARCH QUESTION: What are the reproductive outcomes of women aged 43 years and older undergoing IVF and intracytoplasmic sperm injection (ICSI) treatment using their own eggs. DESIGN: Retrospective study of 833 woman aged 43 years or older undergoing their first IVF and ICSI cycle using autologous oocytes at a tertiary referral hospital between January 1995 and December 2019. Live birth rate (LBR) after 24 weeks' gestation was the primary outcome. RESULTS: Ninety-five out of 833 (11.4%) had a positive HCG, whereas 59 (62.1% per positive HCG) had a miscarriage before 12 weeks' gestation and 36 (4.3%) live births were achieved. Analysis by age showed that the number of cumulus-oocyte complexes retrieved was significantly different between the four age groups: 43 years (5 [3-9]); 44 years (5 [2-7]); 45 years (3 [2-8)]); ≥45 years (2.5 [2-6]); P < 0.01; the number of metaphase II oocytes, however, was similar. Positive HCG rates remained low: 43 years (78/580 [13.4%]); 44 years (14/192 [7.3%]); 45 years (1/39 [2.6%]; and ≥46 years (2/22 [9.1%]); P = 0.03, as did LBR: 43 years (28 [4.8%]); 44 (7 [3.6%]); 45 years (0 [0%]); and ≥46 years (1 [4.5%]); P = 0.5. Multivariate regression analysis revealed that only number of metaphase II was significantly associated with LBR, when age was considered as a continuous (OR 1.08, 96% CI 1.004 to 1.16) or categorical variable (OR 1.08, 95% CI 1.005 to 1.16). CONCLUSION: The chances of achieving a live birth in patients aged 43 years and older undergoing IVF/ICSI with their own gametes are low, even in cases of patients with a relatively 'normal' ovarian reserve for their age.

Fertility preservation does not delay the initiation of chemotherapy in breast cancer patients treated with adjuvant or neo-adjuvant chemotherapy.

PURPOSE: To investigate whether fertility preservation (FP) in adult women diagnosed with breast cancer (BC) may impact the time interval between diagnosis and start of chemotherapy in an adjuvant or neo-adjuvant setting. METHODS: Retrospective cohort study of breast cancer patients diagnosed between January 2012 and December 2017 undergoing FP at a tertiary-care academic fertility centre before neo-adjuvant (NAC) or adjuvant chemotherapy (AC), and matched control breast cancer patients who had no FP. FP interventions included oocyte vitrification following ovarian stimulation or after in-vitro maturation (IVM) of immature oocytes, and/or ovarian tissue cryopreservation. Controls from the patient database of the affiliated Breast Cancer Clinic were matched for tumour characteristics and type of treatment. Time intervals between cancer diagnosis and the start of chemotherapy were analysed. RESULTS: Fifty-nine BC patients underwent FP: 29 received NAC and 30 received AC. The average interval between diagnosis and chemotherapy in BC patients with NAC was 28.5 days (27.3 (range: 14.0-44.0) days in cases and 29.6 (range: 14.0-62.0) days in controls (NS)); this interval was 58.9 days in BC patients with AC (57.2 (range: 36.0-106.0) days in cases and 60.7 (range: 31.0-105.0) days in controls (NS)). CONCLUSION: Fertility preservation does not delay the start of chemotherapy in breast cancer patients.

Testicular immune cells and vasculature in Klinefelter syndrome from childhood up to adulthood.

STUDY QUESTION: Is the distribution of immune cells and the testicular vasculature altered in testicular biopsies from patients with Klinefelter syndrome (KS)? SUMMARY ANSWER: Increased numbers of macrophages and mast cells, an increased expression of decorin and an increased blood vessel density were found in KS samples compared to controls. WHAT IS KNOWN ALREADY: Most KS patients are infertile due to an early germ cell loss. From puberty onwards, testicular fibrosis can be detected. How this fibrotic process is initiated remains unknown. STUDY DESIGN, SIZE, DURATION: In this study, the number of macrophages, mast cells and their secretory products were evaluated in KS, Sertoli cell only (SCO) and control patient samples. The association between immune cell numbers and level of fibrosis in KS tissue was examined. In addition, the vascularization within these testicular tissue biopsies was studied. For immunohistochemical evaluation, KS patients at different stages of testicular development were included: prepubertal (aged 4-7 years; n = 4), peripubertal (aged 11-17 years; n = 21) and adult (aged >18 years; n = 37) patients. In addition, testicular tissue biopsies of adult SCO (n = 33) and control samples for the three KS age groups (prepubertal n = 9; peripubertal n = 5; adult n = 25) were analysed. Gene expression analysis was performed on adult testicular tissue from KS (n = 5), SCO (n = 5) and control (n = 5) patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Adult (>18 years) KS, SCO and control testicular tissue biopsies were obtained during a testicular sperm extraction procedure. KS peripubertal (11-18 years), prepubertal (<11 years) and age-matched control biopsies were obtained from the biobank of the university hospital. Immunohistochemistry was used to determine the tubular structure (H/PAS), the number of spermatogonia (MAGE-A4), macrophages (CD68) and mast cells (tryptase) and the blood vessel density (Von Willebrand factor). In addition, quantitative real-time polymerase chain reaction was used to determine the expression of secretory products of macrophages and mast cells (tryptase, tumour necrosis factor alpha and decorin). MAIN RESULTS AND THE ROLE OF CHANCE: A significant increase in the number of macrophages (P < 0.0001) and mast cells (P = 0.0008) was found in the peritubular compartment of testes of adult KS patients compared to control samples. However, no association between the number of immune cells and the degree of fibrosis was observed. In adult SCO samples, a significant increase was seen for peritubular macrophage (P < 0.0001) and mast cell (P < 0.0001) numbers compared to control samples. In the interstitial compartment, a significant increase in mast cell number was found in adult SCO samples compared to KS (P < 0.0001) and control (P < 0.0001) tissue. A significant difference (P = 0.0431) in decorin expression could be detected in adult KS compared to control patients. Decorin expression was mostly seen in the walls of the seminiferous tubules. When comparing the vascularization between KS patients and age-matched controls, a significant increase (P = 0.0081) in blood vessel density could be observed only in prepubertal KS testicular tissue. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: As controls for this study, testicular tissue biopsies of men who underwent a vasectomy reversal or orchiectomy were used, but these men may not represent fertile controls. In addition, a high variability in immune cell numbers, secretory products expression and number of blood vessels could be observed amongst all patient samples. WIDER IMPLICATIONS OF THE FINDINGS: Increased numbers of macrophages and mast cells have previously been described in non-KS infertile men. Our results show that these increased numbers can also be detected in KS testicular tissue. However, no association between the number of macrophages or mast cells and the degree of fibrosis in KS samples could be detected. Decorin has previously been described in relation to fibrosis, but it has not yet been associated with testicular fibrosis in KS. Our results suggest a role for this proteoglycan in the fibrotic process since an increased expression was observed in adult KS tissue compared to controls. Impaired vascularization in KS men was suggested to be responsible for the KS-related disturbed hormone levels. Our results show a significant difference in blood vessel density, especially for the smallest blood vessels, between prepubertal KS samples and age-matched controls. This is the first study to report differences between KS and control testicular tissue at prepubertal age. STUDY FUNDING/COMPETING INTEREST(S): The project was funded by grants from the Vrije Universiteit Brussel (E.G.) and the scientific Fund Willy Gepts from the UZ Brussel (D.V.S.). D.V.S. is a post-doctoral fellow of the Fonds voor Wetenschappelijk Onderzoek (FWO; 12M2819N). No conflict of interest is declared for this research project.