An Open Prospective Study on Whether Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) Offers a Better Outcome Than Conventional Intracytoplasmic Sperm Injection (ICSI).

Objective To differentiate the in vitro fertilization (IVF) outcomes between the two procedures, intracytoplasmic morphologically selected sperm injection (IMSI) and intracytoplasmic sperm injection (ICSI) in terms of relation to chemical pregnancy percentage, clinical pregnancy, live birth, miscarriage, and fertilization rates, respectively. Patients and methods This Open Prospective clinical trial was conducted during the period between Jan 2016 and Dec 2017 at one IVF unit. A total of 446 ICSI cycles and 79 IMSI cycles were conducted. Females were divided into four subgroups according to age. Results The study involved 525 couples (446 first trial ICSI cycles) and (79 first trial IMSI cycles). ICSI was statistically better than the IMSI in relation to the chemical pregnancy, clinical pregnancy (CPR), live birth (LBR), and fertilization rates, respectively (p < 0.05). However, there were no statistically significant differences between the ICSI and IMSI in relation to the miscarriage rate. There were statistically significant differences favoring ICSI in all subgroups except 35-37, in relation to chemical pregnancy; and in the 38-40 and >40 subgroups in relation to CPR. There were no statistically significant differences in these subgroups regarding the live birth, miscarriage, or fertilization rates. Conclusions This study showed that IMSI is not superior to conventional ICSI at the first attempt. Based on the findings in this study, we would not advise couples to choose IMSI at their first treatment attempt.

Improved cryopreservation of spermatozoa using vitrification: comparison of cryoprotectants and a novel device for long-term storage.

STUDY QUESTION: Does cryoprotection of spermatozoa using a vitrification protocol with improved cryoprotective agents and a novel device for large storage lead to better outcomes than conventional slow freezing? Vitrification of human sperm using sucrose and dextran-based cryoprotectant (CPA4) with a new vitrification device resulted in significantly better sperm motility and progressive motility and improved DNA integrity with lower DNA fragmentation compared with conventional slow freezing. WHAT IS KNOWN ALREADY: A major limitation to clinical implementation of vitrification is the right balance between the volume of spermatozoa suspension cryopreserved and a standardised use of CPAs for survival of spermatozoa. STUDY DESIGN, SIZE, DURATION: This was a control versus current clinical practice study using 30 fresh human semen samples to carry out the different cryoprotectant analyses followed by a further 23 semen samples to test the novel vitrification protocol. PARTICIPANTS/MATERIALS, SETTING, METHODS: All human specimens fulfilled the following criteria: > 5 million spermatozoa/mL, > 20% total motility, ≥ 1.8 mL in volume, with all participants falling within the age range of 25-45 inclusively. The concentration, progressive motility, non-progressive motility, immotility, and various morphokinetic variables including DAP, DCL, DSL, LIN, and STR were then determined using the IVOS II™ Clinical CASA system (Hamilton Thorne, Beverly, MA, USA) on the basis of the 5th Edition of WHO Laboratory Manual for the Examination and Processing of Human Semen. MAIN RESULTS AND THE ROLE OF CHANCE: Among the 6 cryopreservation methods in this study, vitrification with the funnel-shaped device using CPA4 best preserves the 13 sperm parameters evaluated by CASA system. Conventional slow freezing and vitrification with the device using seminal plasma also protects sperm quality, but the overall motilities are statistically lower in comparison with the novel vitrification approach with cryoprotective media using the device. DNA fragmentation significantly increased after cryopreservation through the method of conventional slow freezing (p = 0.07). There was no significant difference in DNA fragmentation between fresh control and vitrification (p = 1.000). LIMITATIONS, REASONS FOR CAUTION: Extensive training is required to minimise the human error in using the vitrification device to perform cryopreservation. Each operator can only handle one sample at a time with device vitrification, whereas several samples can be processed without the need for special training with conventional slow freezing. WIDER IMPLICATIONS OF THE FINDINGS: The presented study shows that a new vitrification method could improve survival sperm rate. Human sperm vitrification using our novel protocol gives higher motility and progression and lower percentage of DNA fragmentation than conventional slow freezing. Our findings indicate that this method could supersede the current clinical practice in particular for patients with oligospermia as it reduces osmotic damage, time, and cost.

Functional assessment for elimination of mismatches in nuclear and whole cell extracts obtained from mouse and human blastocysts.

Preimplantation embryos may have an increased risk of having mismatches due to the rates of cell proliferation and DNA replication. Elimination of mismatches in human gametes and embryos has not been investigated. In this study we developed a sensitive functional assay to examine the repair or elimination of mismatches in both commercially available cell extracts and extracts obtained from preimplantation embryos. Heteroduplex molecules were constructed using synthetic oligonucleotides. Efficiency of the repair of mismatches was semi-quantitatively analysed by exposure to nuclear/whole cell extracts (as little as 2.5 µg) and extracts obtained from pooled mouse and human blastocysts to investigate the repair capacity in human embryos. A cell free in vitro assay was successfully developed to analyze the repair of mismatches using heteroduplex complexes. The assay was further optimized to analyze repair of mismatches in cell extracts obtained from oocytes and blastocysts using minute amounts of protein. The efficiency of mismatch repair was examined in both mouse and human blastocysts (2.5 µg). The blastocysts were observed to have a lower repair efficiency compared to commercially available nuclear and whole cell extracts. In conclusion, a sensitive, easy, and fast in vitro technique was developed to detect the repair of mismatch efficiency in embryos.

Differential expression of parental alleles of BRCA1 in human preimplantation embryos.

Gene expression from both parental genomes is required for completion of embryogenesis. Differential methylation of each parental genome has been observed in mouse and human preimplantation embryos. It is possible that these differences in methylation affect the level of gene transcripts from each parental genome in early developing embryos. The aim of this study was to investigate if there is a parent-specific pattern of BRCA1 expression in human embryos and to examine if this affects embryo development when the embryo carries a BRCA1 or BRCA2 pathogenic mutation. Differential parental expression of ACTB, SNRPN, H19 and BRCA1 was semi-quantitatively analysed by minisequencing in 95 human preimplantation embryos obtained from 15 couples undergoing preimplantation genetic diagnosis. BRCA1 was shown to be differentially expressed favouring the paternal transcript in early developing embryos. Methylation-specific PCR showed a variable methylation profile of BRCA1 promoter region at different stages of embryonic development. Embryos carrying paternally inherited BRCA1 or 2 pathogenic variants were shown to develop more slowly compared with the embryos with maternally inherited BRCA1 or 2 pathogenic mutations. This study suggests that differential demethylation of the parental genomes can influence the early development of preimplantation embryos. Expression of maternal and paternal genes is required for the completion of embryogenesis.

The impact of mosaicism in preimplantation genetic diagnosis (PGD): approaches to PGD for dominant disorders in couples without family history.

OBJECTIVES: Mosaicism in certain dominant disorders may result in a 'non-Mendelian' transmission for the causative mutation. Preimplantation genetic diagnosis (PGD) is available for patients with inherited disorders to achieve an unaffected pregnancy. We present our experience for two female patients with different dominantly inherited autosomal disorders; neurofibromatosis type 1 (NF1) and tuberous sclerosis complex type 2 (TSC2). METHODS: PGD protocol development was carried out using single cells from the patients. PGD was carried out on polar bodies and different embryonic cells. RESULTS: Protocol development for NF1 using lymphocytes from the patient suggested mosaicism for the mutation. This was supported further by quantitative fluorescent-PCR performed on genomic DNA. During PGD, polar bodies and blastomeres lacked the mutation that probably was absent or present at very low levels in the patient's germline. Single lymphocyte analysis during protocol development for TSC2 did not indicate mosaicism; however, analysis of single buccal cells and multiple embryo biopsies across two consecutive IVF/PGD cycles confirmed gonosomal mosaicism. CONCLUSIONS: The trend in PGD is for blastocyst biopsy followed by whole genome amplification, eliminating single cell analysis. In the case of certain dominantly inherited disorders, pre-PGD single cell analysis is beneficial to identify potential mosaicism that ensures robust protocols. © 2016 John Wiley & Sons, Ltd.

Successful outcomes achieved in assisted reproduction cycles using sperm with high levels of high DNA stainability.

The sperm chromatin structure assay (SCSA) has been proposed as a useful addition to the battery of tests routinely used to explore semen quality and hence to give an indication of the likelihood of a successful pregnancy. As usually performed at present, the assay yields two main sperm variables, the DNA fragmentation index (DFI) and the high DNA stainability (HDS). In the present study 275 patients undergoing 215 in vitro fertilization (IVF) and 215 intracytoplasmic sperm injection (ICSI) cycles were studied with the purpose of defining the clinical significance of HDS in IVF and ICSI cycles. Using the Spearman correlation test there were no significant statistical relationships between %HDS and fertilization rate, rate of embryo growth, blastocyst rate, implantation rate, or live birth rate. Rate of pregnancy loss showed a negative relationship significant at the 0.05 level which is unexplained. It is not known whether the normal practice of using processed sperm for fertilization plays any part in this lack of a negative effect of HDS level upon the stages of the cycle. A total of 16 patients with HDS levels >28% had an average live birth rate of 47.8% and an average pregnancy loss of 8.7%, which compared favourably with the group of patients as a whole.

Factors influencing intracytoplasmic sperm injection (ICSI) outcome in men with azoospermia.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The management of patients with non-obstructive azoospermia (NOA) and some cases of obstructive azoospermia involves testicular sperm extraction (TESE or micro-dissection TESE) combined with intracytoplasmic sperm injection (ICSI). Several studies have investigated the effect of the male age, the cause of azoospermia, testicular histopathology, the type of sperm used, and the use of pentoxyphilline, on the ICSI cycle outcome in men with azoospermia. The present study showed that none of these factors influenced the ICSI outcome in men with azoospermia, thus once sperm is found in an azoospermic male, no other male factor seems to influence the ICSI outcome. To our knowledge this is the first study to comment on the outcome of ICSI in men with NOA based on testicular histopathology. OBJECTIVES: To access the effect of: male age, the cause of azoospermia (obstructive azoospermia vs non-obstructive azoospermia [NOA]), testicular histopathology, the type of sperm used (fresh vs frozen-thawed), and the use of pentoxyphilline on the intracytoplasmic sperm injection (ICSI) cycle outcome in men with azoospermia. To our knowledge this is the first study to comment on the outcome of ICSI in men with NOA based on testicular histopathology. PATIENTS AND METHODS: A retrospective analysis of 137 testicular sperm extraction-ICSI cycles performed between 2001-2010, involving 103 men with azoospermia, with 26 couples having repeat cycles. RESULTS: Analysis of the results did not show any statistically significant differences in the fertilization, embryo cleavage, clinical pregnancy, live birth and miscarriage rates in relation to the male age, cuase of azoospermia, testicular histopathology, type of sperm used and the use of pentoxyphilline. CONCLUSION: Once sperm is found in a man with azoospermia, no other male factor seems to influence the ICSI outcome.

Male and female meiotic behaviour of an intrachromosomal insertion determined by preimplantation genetic diagnosis.

BACKGROUND: Two related family members, a female and a male balanced carrier of an intrachromosomal insertion on chromosome 7 were referred to our centre for preimplantation genetic diagnosis. This presented a rare opportunity to investigate the behaviour of the insertion chromosome during meiosis in two related carriers. The aim of this study was to carry out a detailed genetic analysis of the preimplantation embryos that were generated from the three treatment cycles for the male and two for the female carrier.Patients underwent in vitro fertilization and on day 3, 22 embryos from the female carrier and 19 embryos from the male carrier were biopsied and cells analysed by fluorescent in situ hybridization. Follow up analysis of 29 untransferred embryos was also performed for confirmation of the diagnosis and to obtain information on meiotic and mitotic outcome. RESULTS: In this study, the female carrier produced more than twice as many chromosomally balanced embryos as the male (76.5% vs. 36%), and two pregnancies were achieved for her. Follow up analysis showed that the male carrier had produced more highly abnormal embryos than the female (25% and 15% respectively) and no pregnancies occurred for the male carrier and his partner. CONCLUSION: This study compares how an intrachromosomal insertion has behaved in the meiotic and preimplantation stages of development in sibling male and female carriers. It confirms that PGD is an appropriate treatment in such cases. Reasons for the differing outcome for the two carriers are discussed.

Expression profiling of DNA repair genes in human oocytes and blastocysts using microarrays.

BACKGROUND: The early preimplantation embryo relies on mRNA and protein from the oocyte to detect DNA damage and activate DNA repair, cell cycle arrest or apoptosis. Expression of some repair genes has been detected in mammalian oocytes and embryos; however, little is known about DNA repair gene expression in human blastocysts. In this study, DNA repair gene expression was investigated in human oocytes and blastocysts to identify the pathways involved at these stages and detect potential differences in repair mechanisms pre- and post-embryonic genome activation. METHODS: Triplicate sets of pooled metaphase II oocytes or blastocysts were processed for analysis using the Human Genome Survey Microarrays V2.0 (Applied Biosystems). RESULTS: Of 154 DNA repair genes investigated, 109 were detected in blastocysts and 107 in oocytes. Among differentially expressed DNA repair genes, 40/55 (73%) had lower expression levels in blastocysts compared with oocytes (P < 0.05, fold change >3). CONCLUSION: Despite experimental limitations due to culture or freezing and thawing of samples, large numbers of repair genes were detected indicating that all DNA repair pathways are potentially functional in human oocytes and blastocysts. The higher mRNA level for most repair genes in oocytes compared with blastocysts ensures sufficient availability of template until embryonic genome activation.

Preimplantation genetic diagnosis for myotonic dystrophy type 1 in the UK.

Myotonic dystrophy type 1 (DM1) is a dominant multisystemic disorder caused by expansion of a trinucleotide repeat in a non-coding region of DMPK. Prenatal diagnosis (PND) is available; however, the decision to terminate affected pregnancies is difficult as the extent of disability is hard to predict from the size of the expansion. In preimplantation genetic diagnosis (PGD) genetic analysis is carried out before the establishment of pregnancy. This paper reviews the largest number of cycles of PGD for DM1 in the UK indicating that PGD is a practical option for affected couples.

Preimplantation genetic diagnosis for myotonic dystrophy type 1: detection of crossover between the gene and the linked marker APOC2.

OBJECTIVE: To report two cases of preimplantation genetic diagnosis (PGD) for myotonic dystrophy type I (DM1) where cross-over between the DMPK locus and a linked polymorphic marker APOC2 was detected. METHODS: Embryos from in vitro fertilisation (IVF) were biopsied at day 3 of development and single blastomeres collected. Diagnosis was performed by duplex or triplex fluorescent-polymerase chain reaction (F-PCR) to amplify DMPK and APOC2 loci, or DMPK with APOC2 and D19S112 polymorphic markers. RESULTS: A total of 22 oocytes were retrieved from the two patients, 20 were inseminated of which 15 fertilized (75%) and were suitable for biopsy on day 3. A diagnosis was obtained for 12 embryos (80%) and was confirmed in all un-transferred embryos. Crossover between DM1 and APOC2 was detected in two embryos from the two different couples. Transfer of two embryos took place in both cases resulting in two pregnancies. Each couple have had a healthy baby. CONCLUSION: The above cases highlight the importance of using more than one linked polymorphic marker in PGD-PCR protocols and emphasize the danger of using APOC2 as the sole marker to identify the DM1 mutation.

Complete cytogenetic investigation of oocytes from a young cancer patient with the use of comparative genomic hybridisation reveals meiotic errors.

OBJECTIVES: The complete cytogenetic investigation of human oocytes and the corresponding first polar bodies (PBs) derived from an 18-year old female cancer patient. METHODS: A whole-genome amplification method combined with comparative genomic hybridisation (CGH) was employed for the analysis of 14 oocytes and their corresponding first PBs. RESULTS: Chromosome abnormalities were detected in two oocyte-PB complexes. One oocyte had lost X-chromosome material (23,X,-Xcht), while its corresponding first PB showed the reciprocal gain (23,X,+Xcht). Double aneuploidy involving loss of chromatids for chromosomes X and 21 was identified in another first PB (23,X,-21cht,-Xcht). Aneuploidy was attributed to unbalanced pre-division of chromatids at meiosis I. CONCLUSIONS: Meiotic errors in chromosome segregation can occur even in oocytes derived from young women, confirming the existence of age-independent factors contributing to aneuploidy. Such factors are of relevance to fertility, miscarriage and preimplantation aneuploidy screening for the purposes of increasing IVF success rates. The reliability of CGH in examining the whole chromosome complement of a single cell and of being able to detect chromatid anomalies is confirmed by this study.

Preimplantation genetic diagnosis for single gene disorders: experience with five single gene disorders.

We report our experience of 14 preimplantation genetic diagnosis (PGD) cycles in eight couples carrying five different single gene disorders, during the last 18 months. Diagnoses were performed for myotonic dystrophy (DM), cystic fibrosis (CF) [Delta F508 and exon 4 (621+1 G>T)], fragile X and CF simultaneously, and two disorders for which PGD had not been previously attempted, namely neurofibromatosis type 2 (NF2) and Crouzon syndrome. Diagnoses for single gene disorders were carried out on ideally two blastomeres biopsied from Day 3 embryos. A highly polymorphic marker was included in each diagnosis to control against contamination. For the dominant disorders, where possible, linked polymorphisms provided an additional means of determining the genotype of the embryo hence reducing the risk of misdiagnosis due to allele dropout (ADO). Multiplex fluorescent polymerase chain reaction (F-PCR) was used in all cases, followed by fragment analysis and/or single-stranded conformation polymorphism (SSCP) for genotyping. Embryo transfer was performed in 13 cycles resulting in one biochemical pregnancy for CF, three normal deliveries (a twin and a singleton) and one early miscarriage for DM and a singleton for Crouzon syndrome. In each case the untransferred embryos were used to confirm the diagnoses performed on the biopsied cells. The results were concordant in all cases. The inclusion of a polymorphic marker allowed the detection of extraneous DNA contamination in two cells from one case. Knowing the genotype of the contaminating DNA allowed its origin to be traced. All five pregnancies were obtained from embryos in which two blastomeres were biopsied for the diagnosis. Our data demonstrate the successful strategy of using multiplex PCR to simultaneously amplify the mutation site and a polymorphic locus, fluorescent PCR technology to achieve greater sensitivity, and two-cell biopsy to increase the efficiency and success of diagnoses.