Morphokinetics of embryos after IMSI versus ICSI in couples with sub-optimal sperm quality: A time-lapse study

Non-invasive pre-implantation genetic testing's reliability for aneuploidy using Cell-free DNA in embryo culture media

OBJECTIVE

The presence of embryonic cell-free DNA (cfDNA) in spent embryo culture media (SECM) may offer valuable advantages for non-invasive testing of embryo ploidy or genetic characteristics compared to trophectoderm (TE) biopsy. This study aimed to assess the diagnostic potential of SECM cfDNA as a non-invasive sample for chromosomal copy number testing in blastocysts within the clinical setting of in-vitro fertilization.

METHOD

This prospective observational study collected 28 SECM cfDNA samples matched with TE biopsy samples from 21 infertile couples who underwent IVF-PGT-A cycles. SECM samples were obtained from blastocysts that were cultured for approximately 5/6 days in an uninterrupted time-lapse incubator. Both sets of samples were collected during the biopsy procedure. The Variseq Illumina platform was utilized for ploidy measurement. The study evaluated the informativity and interpretability of SECM cfDNA, concordance of general ploidy status, and sex chromosome agreement between the two sample types.

RESULTS

SECM cfDNA had a high informativity rate (100 %) after double amplification procedure, with a result interpretability of 93 %. Two out of the 28 SECM cfDNA samples were uninterpretable and regarded as overall noise samples. The diagnostic potential of SECM cfDNA, when compared to TE biopsy the standard reference, was relatively low at 50 %. Maternal DNA contamination remains the major obstacle that hinders the widespread clinical adoption of SECM cfDNA in the routine practice of pre-implantation genetic testing for aneuploidy within IVF settings.

CONCLUSION

A significant modification must be implemented in the IVF laboratory to minimize DNA contamination and this necessitates suggesting adjustments to oocyte denudation, embryo culture media preparation, and sample collection procedures.

First-line infertility treatment in normal or subnormal sperm: Interest of a simplified pre-IMSI test

BACKGROUND

In the field of male infertility, when sperm is normal/subnormal, a few "add-on" routine tests can complete the basic semen examination.

OBJECTIVES

The aim of this study was to develop and evaluate a faster, simplified motile sperm organelle morphology examination (MSOME) technique for selected infertile patients with apparently normal/subnormal sperm and, in their background: failure of two or three intrauterine insemination (IUI) cycles, repeatedly fragmented embryos, embryonic development to blastocyst-stage failures, repeated miscarriages, a long period of infertility or 2 or more IVF attempts without pregnancy. Our test results were correlated with IUI, conventional in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and intracytoplasmic morphologically selected sperm injection (IMSI) outcomes.

MATERIALS AND METHODS

We validated an adapted version of the MSOME analysis called the pre-IMSI test (PIT), based on vacuole evaluation alone. 248 infertile patients from our assisted reproductive technology (ART) Center were retrospectively selected and split into three PIT score subgroups (patients with ≤8% (score I), 9 to 15% (score II) and ≥16% normal spermatozoa (score III)) based on the correlation between PIT results and each ART technique outcome. The choice of one or another of these ART techniques had been made according to the usual clinico-biological criteria.

RESULTS

Clinical outcomes for each of the three PIT subgroups were compared individually for the different ART techniques. For ICSI, the effect of the PIT score subgroup was significant for clinical pregnancies (p = 0.0054) and presented a trend for live births (p = 0.0614). Miscarriage rates of IVF attempts were statistically different depending on the PIT score (p = 0.0348). Furthermore, the odds ratios of clinical pregnancy rates were significantly different according to PIT score subgroup when comparing ICSI vs. IMSI or IVF vs. ICSI attempts.

DISCUSSION

IMSI appears to be recommended when sperm belongs to PIT score I, ICSI when it belongs to PIT score II and IVF or IUI when sperm is of PIT score III quality in selected infertile couples. The lack of statistical power in these PIT subgroups means that we must remain cautious in interpreting results.

CONCLUSION

Our results support the interest of this simplified test for certain couples with normal/subnormal sperm to help choose the most efficient ART technique, even as first-line treatment.

Utilisation of Oocyte Diameter as a Non-invasive Indicator of Oocyte and Embryo Quality: Investigating Protein Kinase B Protein Expression in Cumulus-Granulosa Cells and Embryo Morphokinetics

Background

Oocyte diameter is crucial for initiating meiosis and supporting the maturation capability, a prerequisite for successful fertilisation and high-quality embryo development. While numerous studies have explored the correlation between oocyte diameter and embryo development capacity in animal models, limited research appears concerning human oocytes.

Aim

This study aims to ascertain whether oocyte diameter can serve as a reliable predictor of oocyte and embryo quality, achieved through its correlation with protein kinase B (Akt) protein levels on cumulus-granulosa cells and blastocyst morphokinetics.

Setting and Design

Prospective cohort study included cumulus-granulosa cells collected from 228 mature oocytes of 32 infertile women undergoing in vitro fertilisation treatment. The diameter of the oocytes was measured using the Image J software, and the samples were categorised into three groups based on their diameter: <105.95 µm, 105.96-118.96 µm and >118.97 µm. Quantification of pAkt and Akt protein total of cumulus-granulosa cells exploited the ELISA method. Embryo morphokinetics and anomaly development events were observed at the blastocyst stage to evaluate embryo quality relative to oocyte diameter.

Statistical Analysis Used

The Kruskal-Wallis test and Chi-square test were used. P <0.05 was considered statistically significant.

Results

The study revealed no notable difference in pAkt and Akt protein total in cumulus-granulosa cells among the three groups (P > 0.05). Likewise, there were no significant differences in morphokinetics and anomaly development except for the S2 parameter and reverse cleavage.

Conclusion

Reflecting on the molecular profile including pAkt, total Akt protein, morphokinetics and anomaly development, it was observed that oocyte diameter does not correlate with its competency and the quality of the resulting embryo. In addition, oocytes with a diameter below 105.95 µm may have an equal potential to develop into top-quality embryos.

Mitochondrial DNA copy number in cumulus granulosa cells as a predictor for embryo morphokinetics and chromosome status

While morphokinetic evaluation of embryos has become the most commonly used technique in IVF to select embryos for transfer, studies have demonstrated that mitochondrial DNA (mtDNA) copy number is correlated with embryo viability and transfer outcomes. Correspondingly, this cohort study aims to evaluate the association between the mtDNA copy number in cumulus granulosa cells (CGCs) with embryo morphokinetic parameters and chromosomal status. Real-time PCR was employed to measure the mtDNA copy number of the 129 CGCs in samples obtained from 30 patients undergoing the IVF-IMSI program at Morula IVF Jakarta between July and October 2020. Bivariate and multiple analyses were utilized to determine its relationship with embryo morphokinetics, blastocyst yield, and chromosomal status. According to the analysis, there was a significant correlation between the mtDNA copy number and the blastocyst status after adjusting for the maternal age and sperm morphology (coefficient 0.832, p value = 0.032, RR value 2.299). Moreover, a significant link was observed between mtDNA copy number in CGC and early embryo developmental phase M1 (t2-t8), using the equation of M1 is 5.702-0.271 mtDNA copy number of CGCs + 0.017 maternal age + 0.013 sperm motility -0.115 sperm morphology (p value = 0.032). However, no correlation was found between the mtDNA copy number in CGCs with the other morphokinetic parameters (M2: tC-tEB, M3: t2-tEB, DC, RC, MN with p > 0.05), or the chromosomal status of the embryos (euploid: 139.44 ± 133.12, aneuploid: 142.40 ± 111.30, p = 0.806). In conclusion, our study suggests that mtDNA copy number in CGCs can serve as a useful biomarker for blastocyst status and early embryo developmental phase but not for chromosomal status.

Advanced Sperm Selection Strategies as a Treatment for Infertile Couples: A Systematic Review

Assisted reproductive technology (ART) is an essential tool to overcome infertility, and is a worldwide disease that affects millions of couples at reproductive age. Sperm selection is a crucial step in ART treatment, as it ensures the use of the highest quality sperm for fertilization, thus increasing the chances of a positive outcome. In recent years, advanced sperm selection strategies for ART have been developed with the aim of mimicking the physiological sperm selection that occurs in the female genital tract. This systematic review sought to evaluate whether advanced sperm selection techniques could improve ART outcomes and sperm quality/functionality parameters compared to traditional sperm selection methods (swim-up or density gradients) in infertile couples. According to preferred reporting items for systematic reviews and meta-analyses (PRISMA guidelines), the inclusion and exclusion criteria were defined in a PICOS (population, intervention, comparator, outcome, study) table. A systematic search of the available literature published in MEDLINE-PubMed until December 2021 was subsequently conducted. Although 4237 articles were recorded after an initial search, only 47 studies were finally included. Most reports (30/47; 63.8%) revealed an improvement in ART outcomes after conducting advanced vs. traditional sperm selection methods. Among those that also assessed sperm quality/functionality parameters (12/47), there was a consensus (10/12; 83.3%) about the beneficial effect of advanced sperm selection methods on these variables. In conclusion, the application of advanced sperm selection methods improves ART outcomes. In spite of this, as no differences in the reproductive efficiency between advanced methods has been reported, none can be pointed out as a gold standard to be conducted routinely. Further research addressing whether the efficiency of each method relies on the etiology of infertility is warranted.

IMSI—Guidelines for Sperm Quality Assessment

Intracytoplasmic sperm injection (ICSI) is a widely used and accepted treatment of choice for oocyte fertilization. However, the quality of sperm selection depends on the accurate visualization of the morphology, which can be achieved with a high image resolution. We aim to correct the conviction, shown in a myriad of publications, that an ultra-high magnification in the range of 6000×–10,000× can be achieved with an optical microscope. The goal of observing sperm under the microscope is not to simply get a larger image, but rather to obtain more detail—therefore, we indicate that the optical system’s resolution is what should be primarily considered. We provide specific microscope system setup recommendations sufficient for most clinical cases that are based on our experience showing that the optical resolution of 0.5 μm allows appropriate visualization of sperm defects. Last but not least, we suggest that mixed research results regarding the clinical value of IMSI, comparing to ICSI, can stem from a lack of standardization of microscopy techniques used for both ICSI and IMSI.