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Study question Does artificial collapse of human blastocysts before vitrification affect the post warming quality of embryos and/or the reproductive outcome? Summary answer This study suggests that artificial collapse with laser pulse before vitrification significantly benefits blastocyst quality post-warming without improving reproductive outcome. What is known already The efficiency of vitrification of blastocysts can be influenced by various factors, such as the stage of the expansion and the quality of the embryos. Expanded blastocysts seem to be more sensitive and prone to cryo-injury during vitrification because of the large amount of blastocoelic fluid which may cause insufficient dehydration. Artificial collapse (AC) with micro-needles or with laser pulse can improve the vitrification procedure and protect the expanded blastocysts from cryoinjuries by reducing the fluid of the blastocoel. Study design, size, duration This prospective randomized study was performed at Embryolab Fertility Clinic, in Thessaloniki, Greece between July 2020 and November 2020 and included 94 ICSI treatments with no fresh embryo transfer. Patients with more than 4 blastocysts were randomized and allocated to the study (AC) group or control group. Randomization list was created by a computer-based program. The embryos were vitrified at the blastocyst stage and the best 1–2 embryos were transferred in a subsequent cycle. Participants/materials, setting, methods Patients were divided in two groups: AC group (n = 46) where 1 or 2 best expanded blastocysts were artificially collapsed by a laser pulse before vitrification and control group (n = 48) where the corresponding best expanded embryos remained untreated before vitrification. The embryos were graded according to Gardner’s criteria and vitrified using open system. Quality of embryos, pregnancy rate and clinical pregnancy rate from the first warming cycle were the parameters that were analyzed using z-test. Main results and the role of chance The analyzed embryos were in total 171, 85 in the AC group and 86 in the control group. The day 5 embryos in each group were 6.89 (±3.41) and 6.50 (±3.38) and the number of embryos per embryo transfer was 1.85 (±0.36) and 1.79 (±0.41) respectively. Cryoinjury was determined as the presence of degenerated cell in ICM or TE. In the AC group cryo-injury was significantly lower than in the control group [31.11% with at least 1 embryo per embryo transfer and 52.08% respectively (p = 0.0356), 6.67% with cryo-injury in both embryos and 14.58% respectively (p Limitations, reasons for caution The number of cases included in this study was limited and the live birth rate was not yet available. More prospective randomized studies are needed in order to validate the benefit of artificial collapse before the vitrification procedure. Wider implications of the findings: Laser artificial Collapse does not compromise expanded blastocyst quality, on the contrary it seems to reduce the amount of cryoinjury observed post warming. Whether it can improve the reproductive outcome, remains to be examined in larger scale studies. Trial registration number Not applicable

Genome-wide association studies have paved the way for the discovery of new markers regarding many diseases, including male infertility. A previous study on Caucasians highlighted 172 polymorphisms for their putative association with male infertility and we attempted to replicate these findings on our dataset comprising of Greek male individuals (n = 360). We retrieved 59 out of 172 polymorphisms and tested for all association models on 278 normospermic men and 82 patients with an abnormal seminogram, later separated into oligozoospermic and asthenozoospermic groups. Our findings indicate that two SNPs (rs2296225 in KIF17, rs7224496 in SMYD4) are associated with male infertility in the Greek population and have not been recorded in literature as of yet. These novel markers need further validation via additional studies and an increased individual number. All in all, replication studies, possess the power to validate existing polymorphisms found across all population and thus increase both statistical significance as well as identify novel potentially diagnostic markers.

BACKGROUND: Male infertility is currently one of the most common problems faced by couples worldwide. We performed a GWAS on Greek population and gathered statistically significant SNPs in order to investigate whether they lie within or near lncRNA regions. OBJECTIVES: The aim of this study was to investigate whether polymorphisms on or near lncRNAs affect interactions with miRNAs and can cause male infertility. MATERIALS AND METHODS: In the present study, a GWAS was conducted, using samples from 159 individuals (83 normozoospermic individuals and 76 patients of known fertility issues). Standard procedures for quality controls and association testing were followed, based on case-control testing. RESULTS: We detected six lncRNAs (LINC02231, LINC00347, LINC02134, NCRNA00157, LINC02493, Lnc-CASK-1) that are associated with male infertility through their interaction with miRNAs. Furthermore, we identified the genes targeted by those miRNAs and highlighted their functions in spermatogenesis and the fertilization process. DISCUSSION AND CONCLUSION: lncRNAs are involved in spermatogenesis through their interaction with miRNAs. Thus, their study is very important, and it may contribute to the understanding of the molecular mechanisms underlying male infertility. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-020-01937-w) contains supplementary material, which is available to authorized users.

The first isolation of human embryonic stem cells (hESC) reported in the late 90s opened a new window to promising possibilities in the fields of human developmental biology and regenerative medicine. Subsequently, the differentiation of hESC lines into different precursor cells showed their potential in treating different incurable diseases. However, this promising field has consistently had remarkable ethical and experimental limitations. This paper is a review of clinical trial studies dealing with hESC and their advantages, limitations, and other specific concerns. Some of the hESC limitations have been solved, and several clinical trial studies are ongoing so that recent clinical trials have strived to improve the clinical applications of hESC, especially in macular degeneration and neurodegenerative diseases. However, regarding hESC-based therapy, several important issues need more research and discussion. Despite considerable studies to Date, hESC-based therapy is not available for conventional clinical applications, and more studies and data are needed to overcome current clinical and ethical limitations. When all the limitations of Embryonic stem cells (ESC) are wholly resolved, perhaps hESC can become superior to the existing stem cell sources. This overview will be beneficial for understanding the standard and promising applications of cell and tissue-based therapeutic approaches and for developing novel therapeutic applications of hESC.

Males with abnormal karyotypes and subgroups of fertile and infertile males with normal karyotypes may be at risk of producing unbalanced or aneuploid spermatozoa. Biological, clinical, environmental and other factors may also cause additional sperm aneuploidy. However, increased risk of sperm aneuploidy is directly related to chromosomally abnormal embryo production and hence to poor reproductive potential. This systemic literature review focuses on the identification of these males because this is an essential step in the context of assisted reproduction. This research may allow for a more personalised and, hence, more accurate estimation of the risk involved in each case, which in turn will aid genetic counselling for affected couples and help with informed decision-making.

In 192 oocyte donation cycles performed between January 1993 and July 1996, we examined the width of 'the window for embryo transfer' using standard hormonal replacement methods. All transfers were performed within 48 h of insemination. We varied the day of embryo transfer with regard to the initiation of progesterone therapy and, thus, the duration of endometrial exposure to progesterone and analysed the resulting pregnancy rates. Patients were divided into five groups (I-V) and embryo transfers were performed 2, 3, 4, 5 or 6 days following initiation of progesterone therapy. The number of pregnancies per transfer cycle achieved in groups I-V were 0 (0%), 3 (12%), 16 (40%), 29 (48.3%), and 10 (20.4%) respectively. The increased pregnancy rate in group III in comparison to group II is statistically significant (P < 0.03). Furthermore, the pregnancy rate in group IV (5 days of progesterone administration before embryo transfer) was significantly higher than in group V (6 days of progesterone administration before embryo transfer; P < 0.005). We also noted that, when embryos were transferred 4 or 5 days after initiation of progesterone therapy, the pregnancy rates were not significantly different between menopausal and cycling recipients (50% vs 43.7%). Our results indicate that the window for embryo transfer is dependent on duration of treatment with progesterone; it begins approximately 48 h after starting progesterone administration and lasts for approximately 4 days. The optimum period for transferring embryos at the 4- to 8-cell stage corresponds to cycle days 18 and 19. Transfers performed on the 17th and 20th days of the cycle can result in successful implantation, although the rates of implantation are highest when transfers are done on days 18 and 19.

Background: Low (or poor) responder patients are women who require large doses of stimulation medications and produce less than an optimal number of oocytes during IVF cycles. Low responder patients produce few oocytes and embryos, which significantly reduces their chances for success in a preimplantation genetic diagnosis (PGD) cycle. Accumulation of vitrified oocytes or embryos before the actual PGD cycle is a possible strategy that might increase patient’s chances for a healthy pregnancy.Aim of the study: This retrospective study evaluates the efficacy of a PGD program in low responder patients after repeated ovarian stimulation cycles with cumulative vitrification of oocytes and embryos.Methods: Over a period of 30 months, 13 patients entering the PGD program were identified as poor responders after their first ovarian stimulation. These patients started a PGD cycle for one of the following indications: history of recurrent implantation failure (n=1), cystic fibrosis (n=1), X-linked microtubular myopathy (n=1), recurrent miscarriages (n=5), Duchene muscular dystrophy (n=1), chromosomal translocation (n=1) and high sperm aneuploidy (n=1). After multiple ovarian hormonal stimulations patients had either all mature oocytes (Group A; 3 patients) or all of their day 2 embryos vitrified (group B; 10 patients). Mean total number of oocyte collections per patient was 2.3 (range: 2 - 5 cycles).Results: In the actual PGD cycle, all vitrified oocytes from group A patients were warmed and underwent intra cytoplasmic sperm injection (ICSI) followed by culture up to day 3. For group B patients all vitrified day 2 embryos were warmed and cultured overnight. On day 3 of culture, all embryos from Group A and B had blastomere biopsy followed by genetic analysis. In group A, 20 embryos were found suitable for biopsy and genetic analysis; at least one healthy embryo was available for transfer for each patient. For group B, 72 embryos in total were available for biopsy and PGD. All patients, except one, had at least one healthy day 5 embryo for transfer (mean number of 2.1 embryos per transfer). Nine patients had a clinical pregnancy; 7 patients delivered a healthy baby.Conclusion: Low responder patients entering a PGD program might increase their chances for a healthy pregnancy by repeat ovarian stimulation in combination with cumulative oocyte or embryo vitrification.

Microinjection of spermatids into oocytes has proven to be a successful assisted reproduction procedure in the animal model. In the human, low fertilization and cleavage to the 4-cell stage were reported after intracytoplasmic sperm injection (ICSI) with round spermatids. In comparison with a conventional ICSI-testicular sperm extraction (TESE) programme, the implantation rate after round spermatid injection is dramatically low. Different problems have been encountered during the development of the spermatid injection technique and they could be partially responsible for the lower outcome when using round spermatids. Compared with the round spermatid cells, spermatids in the elongation phase are easy to isolate and identify from other round cells present in a wet preparation. The morphological identification does not reveal anything about the viability or the genetic normality of the round spermatids. Severe testicular dysfunction may have consequences on the quality of the few spermatogenic cells present. Others factors, such as the pathology of the patient, play an important role in the successful treatment. Even if the results are extremely low, spermatid injection seems more favourable for men who have already proven their capacity to produce some spermatozoa. A spermatogenic block at the round spermatid level has led to early abortions, increasing the suspicion of the role of a genetic factor. In order for this technique to be safe for use in clinics, more intensive work is needed to improve the selection and handling of cells and to ascertain the genomic imprinting and gene expression necessary for embryonic development. Hence, when using immature cells for conception, the screening of the patient and the follow-up of the pregnancies and babies should be mandatory.