Search Results (67)

Background/Objectives: Embryo selection in IVF is traditionally based on morphology, yet many high-quality embryos fail to implant. Preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing (NGS) has been proposed to improve selection by identifying euploid embryos. However, its effectiveness in women of advanced maternal age remains unclear due to limited randomized data. This pilot trial assessed the feasibility of a full-scale RCT comparing PGT-A to morphology-based selection in women aged 35–42. Methods: This single-centre, two-arm parallel RCT (NCT05009745) enrolled women aged 35–42 undergoing IVF/ICSI with ≥3 good-quality day-3 embryos. Participants were randomized (1:1) to either embryo selection by morphology with fresh transfer or PGT-A with frozen transfer of a single euploid embryo. Allocation concealment was achieved via a secure web-based randomization platform; patients and clinicians were unblinded, but the biostatistician remained blinded. The primary outcome was feasibility of recruitment, randomization, and adherence. Results: Between June 2021 and January 2023, 138 women consented (recruitment rate: 55.8%, 95% CI: 49.7–62.0%) and 100 were randomized. Protocol adherence was 94%. Barriers to recruitment included preference for private PGT-A (19%) or fresh transfer (6%). Among biopsied embryos, 51.4% were euploid and 6.6% low-level mosaic. Intention-to-treat analysis showed no significant differences between PGT-A and control groups in clinical pregnancy rate (50% vs. 40%), live birth rate (50% vs. 38%), or miscarriage rate (12% vs. 8%). Cumulative live birth rate after up to three SETs was 72% vs. 52%, respectively (p > 0.05). No multiple pregnancies occurred. Conclusions: RCTs of PGT-A in older women are feasible. A multicentre design with broader inclusion criteria could improve recruitment and allow better assessment of clinical benefit. Full article

This study aimed to compare sperm parameters and reproductive outcomes after sperm selection using microfluidic chips versus conventional techniques (swim-up/density gradients). A systematic review and meta-analysis were performed after the extraction of relevant data from thirty-nine studies that met the inclusion criteria. Mean difference or odds ratio was calculated for each outcome. The analysis revealed that sperm selection using microfluidics yields lower sperm DNA fragmentation (MD = −9.98 [−13.19, −6.76], p < 0.00001), increased progressive motility (MD = 14.50 [7.84, 21.71], p = 0.04), total motility (MD = 10.68 [6.04, 15.31], p < 0.00001) and morphology (MD = 1.41 [0.67, 2.16], p = 0.0002). Significant differences were also found in the fertilization rate/MII oocyte microinjected (OR = 1.22 [1.01, 1.46], p = 0.04), implantation rate/embryo transfer (ET) (OR = 4.51 [1.42, 14.37], p = 0.01), clinical pregnancy/ET (OR = 1.73 [1.22, 2.45], p = 0.002), ongoing pregnancy/ET (OR = 1.99 [1.03, 3.83], p = 0.04), live birth rate/first cycle (OR = 1.59 [1.12, 2.24], p = 0.009) and per all embryo transfer (OR = 1.65 [1.06, 2.55], p = 0.03). No significant differences were found in embryo euploidy/number of biopsied blastocysts (OR = 1.34 [0.88, 2.04], p = 0.77), biochemical pregnancy/ET (OR = 1.23 [0.84, 1.80], p = 0.29), miscarriage rate/cycle (OR = 0.84 [0.54, 1.31], p = 0.35) and per pregnancy (OR = 0.71 [0.50, 1.02], p = 0.07), live birth rate/first embryo transfer (OR = 1.60 [0.80, 3.22], p = 0.18) and per concluded cycle (OR = 1.03 [0.53, 2.00], p = 0.92). To summarize, microfluidics may offer a beneficial approach in certain situations, particularly for patients with elevated sperm DNA fragmentation (SDF) levels. However, its integration into routine clinical practice cannot be justified yet in terms of cost-effectiveness. Additional research is needed to provide more comprehensive data on reproductive outcomes, especially live birth rates, which remain the ultimate goal of assisted reproductive technologies. Full article

Background: Charcot–Marie–Tooth disease (CMT) is a genetically and clinically heterogeneous group of progressive peripheral neuropathies. Preimplantation genetic testing for monogenic disorders (PGT-M), a well-established assisted reproductive technology used to detect specific genetic mutations in embryos before implantation, has been used in common CMT subtypes (e.g., CMT1A); however, data on its application across rarer subtypes and in de novo cases remain limited. In this study, we aimed to evaluate the effectiveness of PGT-M using karyomapping in achieving clinical pregnancies and healthy births in families affected by various CMT types, including the previously unreported subtypes CMT1B and CMT2. Methods: We analyzed 31 PGT-M cycles from 13 families with genetically confirmed CMT, including cases of previously unreported subtypes CMT1B and CMT2. A total of 150 embryos were biopsied. Through 19 embryo transfer cycles, 21 embryos were transferred. In one de novo case, karyomapping was performed using amniotic fluid from an affected fetus as a reference. Results: Of the 19 embryo transfers, 15 resulted in clinical pregnancies. Prenatal diagnosis confirmed that all fetuses were unaffected, and all pregnancies resulted in healthy live births. Successful phasing using amniotic fluid from an affected fetus enabled accurate embryo selection and led to the birth of healthy twins. Conclusions: PGT-M using karyomapping is a rapid and reliable method for achieving successful pregnancies in families affected by diverse CMT subtypes, including de novo cases, and supports broader applicability to other monogenic disorders. Full article

Preimplantation genetic testing for aneuploidy (PGT-A) is widely used to select euploid embryos for in vitro fertilization (IVF), but its accuracy in predicting the implantation potential for full segmental aneuploid (Seg-A) embryos remains unclear. In this study, we investigated chromosomal concordance between clinically biopsied trophectoderm (TE) and inner cell mass (ICM) in 175 donated blastocysts, which comprised those clinically diagnosed as euploid (13), Seg-A (36), segmental mosaicism (Seg-M) (60), whole-chromosome aneuploid (Who-A) (52), and whole-chromosome mosaicism (14). Using next-generation sequencing (NGS), we found that TE–ICM concordance rates were higher for euploid (85%) and Who-A (94%) embryos but significantly lower for Seg-A (25%) and Seg-M embryos (33%). For Seg-A, the euploidy rate in the ICM was 19% and the euploidy rate in the ICM was 63% for Seg-M. These low concordance rates may be due to technical and biological artifacts of PGT-A for Seg-A. Despite the significant discordance between TE and ICM, a subset of Seg-A embryos demonstrated euploidy. While clinically diagnosed euploid embryos remain the preferred choice, Seg-A embryos should be considered as having implantation potential. In particular, Seg-A results should be clearly distinguished from Who-A results and not routinely categorically discarded. Further research is required to refine the selection criteria, aided by parental karyotyping or re-biopsy, and to develop more reliable embryo assessment methods to ensure the accurate evaluation of reproductive potential and support shared decision making between doctors and patients. Full article

Background: Given the common occurrence of mosaicism and aneuploidy in IVF embryos, our study aimed to retrospectively identify whether specific chromosomal regions or individual chromosomes are predominantly affected in our clinic. Understanding these patterns can improve embryo selection, reduce miscarriage risks, and enhance genetic counseling. At the same time, due to the limited data on potential comorbidities in affected children, our findings aim to support both clinicians and patients in making informed decisions. Methods: The retrospective clinical study included 461 PGT-A biopsies from our clinic database (September 2023–December 2024) to determine whether specific chromosome regions or individual chromosomes (C) are more likely to be mosaic or aneuploid. Results: Among the 461 embryos analyzed in our clinic, the incidence rate of mosaicism was 16.70% whereas the aneuploidy rate was 32.10%. Our results showed that mosaicism tends to target a specific chromosomal region in embryos, namely the chromosome 1 to 9 region, in particular chromosomes 7, 1, 9. On the other hand, aneuploidy targets the chromosomal region chromosome 16 to 22, particularly chromosomes 16, 19, and 22. Conclusions: Our data suggest that mosaicism and aneuploidy affect the genome in an uneven manner and are often concentrated in specific chromosomal regions, with mosaicism primarily affecting the C1–C9 region and aneuploidy targeting the C16–C22 region. These data highlight the need for further research to understand these patterns and the impact of IVF methods on chromosomal targeting. Comparative studies could also be helpful in genetic counseling by clarifying the implications of the levels of mosaicism in the newborn. Full article

Background/Objectives: Male infertility is becoming a serious problem affecting about 7% of all men worldwide and is a major or contributory factor in 50% of infertile couples overall. Men with abnormal semen parameters have a significantly increased risk of aneuploidy, presenting a serious concern in programmes of assisted reproductive technologies. Recently, the introduction of preimplantation genetic testing for aneuploidies (PGT-A) has increased the pregnancy rate and live births. We investigated the effect of PGT-A on the success of IVF treatment in couples with the male factor of infertility. Methods: Two experimental groups and one control group were studied: Group A (110 couples)—male partners with abnormal semen parameters, with PGT-A; Group B (110 couples)—male partners with abnormal semen parameters, without PGT-A; and Group C (105 couples)—control, male partners with normal spermograms, with PGT-A. A Day 3 blastomere biopsy was followed by FISH-based PGT-A. A total of 880 embryos from Group A and 890 embryos from Group C was analysed. Results: In patients with abnormal semen parameters, embryonic aneuploidy was twice as common compared to the control (13.6% vs. 5.8%, p < 0.001). Group B had the lowest clinical pregnancy rate (28.2%), with two out of three pregnancies ending in a miscarriage. Only 10% of IVF cycles in this group resulted in live birth compared with 35.5% for Group A and 49.5% for Group C. Conclusions: Our data demonstrate that PGT-A screening as part of IVF treatment drastically increases the clinical pregnancy rate and chances of live birth in couples where male partners have semen abnormality. Full article

To minimise the influence of chromosomal abnormalities during IVF treatment, embryos can be screened before transfer using preimplantation genetic testing. This typically involves an invasive trophectoderm biopsy at the blastocyst stage, where 4–8 cells are collected and analysed. However, emerging evidence indicates that, as embryos develop in vitro in culture media, they release cell-free DNA into the media, providing an alternative source of genetic material that can be accessed non-invasively. Spent blastocyst media samples that contain embryo cell-free DNA demonstrate high informativity rates and ploidy concordance when compared with the corresponding trophectoderm, inner cell mass, or whole blastocyst results. However, optimising this non-invasive approach requires several changes to embryo culture protocols, including additional embryo washes to tackle contamination and extending embryo culture time to maximise the amount of cell-free DNA released into the culture media. In this review, we discuss this novel non-invasive approach for aneuploidy detection and embryo prioritisation, as well as the current data and future prospects for utilising cell-free DNA analysis to identify structural rearrangements and single gene disorders. Full article

Time-lapse imaging has made possible the detailed observation of all stages of embryonic development, including also from the extrusion of the second polar body up to the first cleavage. By extensive observation, we achieved detection of a variety of behaviors of PBIIs such as (a) morphologically static behavior, (b) amoeboid movement, (c) shrinking, (d) fragmenting, and (e) ruffling. Retrospective analysis was performed on 282 ICSI zygotes derived from 69 ART treatment cycles from January to August 2019. Zygotes with morphologically static PBIIs (a) and PBIIs showing various behaviors (b)~(e) were classified into Group 1 (n = 70) and Group 2 (n = 212), respectively. Based on the rates of irregular division, good quality embryos, and the time from the PBII extrusion, pronuclear breakdown to the first cleavage was compared between groups (Study 1). Furthermore, the relationship between the type of PBII behaviors and ploidy in 94 biopsied blastocysts from 15 cycles was examined, in which one or more euploid embryos were obtained between August 2021 and July 2024 (Study 2). The results showed that good quality embryos tended to have morphologically static PBIIs, and that euploid embryos were absent in embryos with fragmenting and ruffling PBIIs. The behavior of PBIIs may be a new predictor of embryonic developmental potential, and, in the future, morphokinetic behaviors of PBIIs may be a useful parameter for AI-assisted embryo evaluation systems. Full article

Alpha-fetoprotein (AFP) is measured during pregnancy in maternal serum to screen for, and in amniotic fluid to test for, neural tube defects. This study aimed to determine whether or not AFP is expressed in blastocoel fluid-conditioned media (BFCM) at the blastocyst stage of embryonic development. For this in vitro study, BFCM was obtained from blastocyst stage embryos following standard embryology laboratory processes. Good quality blastocysts (n = 40) had trophectoderm biopsy for preimplantation genetic testing for aneuploidy (PGT-A) with subsequent blastocyst vitrification and BFCM collection. BFCM samples (n = 40) were analyzed for human AFP protein via an AFP Human ELISA Kit. Statistical analysis was performed with Fisher’s exact test. AFP was expressed in 12.5% (5/40) of BFCM samples (range = 1.69–20.5 pg/mL). Of blastocysts with AFP in BFCM, 80% (4/5) had aneuploid PGT-A results; of blastocysts with no AFP in BFCM, 57% (20/35) had aneuploid PGT-A results, with no difference between groups (p = 0.63). Our study demonstrates AFP expression in BFCM. To our knowledge, this is the first study to report the detection of AFP at the embryonic blastocyst stage in vitro. Future studies are needed and underway to determine whether assessment of AFP at the embryonic stage can improve embryo transfer outcomes. Full article

Trophectoderm (TE) biopsy is at present the most widely used procedure for preimplantation genetic testing (PGT). At the blastocyst stage, more TE cells (five to seven) can be obtained for genetic analysis. While removing TE cells and not touching the inner cell mass (ICM), the procedure is less invasive. Due to a natural selection happening between day 3 and day 5, 6 or 7 of human embryo development, fewer embryos will have to be biopsied and tested. An additional benefit, especially in view of aneuploidy testing (PGT-A), is the lower level of mosaicism present at the blastocyst stage. The biopsy procedure involves two steps: laser-assisted zona pellucida (ZP) opening and the excision of five to eight TE cells from the blastocyst with or without additional laser energy. Different protocols have emerged over time with variations regarding the technique, the exact moment of ZP opening, and the method of cell removal. The ‘pulling’ method involves laser excision, whereas the ‘flicking’ method represents a mechanical approach with or without laser assistance. Embryo developmental speed reaching the full/expanded or hatching/hatched blastocyst stage dictates the timing of the procedure, mostly on day 5 post-insemination, and to a lesser extent on day 6 or even on day 7. The inclusion of lesser quality or delayed blastocysts may impact the quality of the TE sample as well as the clinical outcome. Intracytoplasmic sperm injection (ICSI) is still the preferred method of fertilization for PGT-M (monogenic disorders) and PGT-SR (structural rearrangements). However, conventional in vitro fertilization (IVF) seems feasible for PGT-A (aneuploidy testing). In the absence of a (conclusive) genetic result, the re-biopsy of cryopreserved blastocysts is possible, however, with reduced clinical outcomes. So far, neonatal outcome post-TE biopsy has so far been reassuringly documented. Full article

Objective: Abnormally fertilized embryos are often discarded during in vitro fertilization due to the fact that known chromosomal ploidy abnormalities lead to implantation failure or pregnancy loss. The objective of this study was to determine if pronuclear numeration (PN) observed at fertilization check is representative of the true ploidy status of the subsequent developing blastocyst in order to maximize the number of viable embryos available for infertility patients and increase their chances of conception. Methods: Upon successful fertilization, pronuclear numeration was noted, and zygotes were cultured to the blastocyst stage. Biopsied trophectoderm cells were then lysed, and the isolated DNA was whole-genome amplified followed by library preparation. Next-generation sequencing was performed for PGT-A, and excess whole-genome amplified DNA was utilized for single nucleotide polymorphism beadchip array analysis. Results: At the time of fertilization check on day 1 of embryo development, when there were no visible pronuclei (n = 291), 56% of these 0PN blastocysts were confirmed to be diploid and normally fertilized. The remaining 41.9% were aneuploid, and 2.1% of the 0PN blastocysts contained only 23 haploid chromosomes. Upon analysis of the 1PN blastocysts (n = 217), just over a third (36.4%) only contained 23 haploid chromosomes (23XO), with another third (31.8%) identified as aneuploid, and surprisingly, the remaining third (31.8%) confirmed to be diploid and normally fertilized. In contrast, 50% of the 3PN blastocysts (n = 172) showed the presence of a third set of 23 parental chromosomes and were confirmed to be triploid (69XXY = 59.3% and 69XXX = 40.7%), with 41.9% identified as aneuploid and, interestingly, a small percentage (8.1%) confirmed to be diploid with normal fertilization. A very small proportion of biopsied blastocysts (0.63%) displaying the correct number of pronuclei for normal fertilization (2PN) were also identified as triploid with a third set of 23 parental chromosomes. To date, there have been 74 euploid embryo transfers from zygotes originally identified with an alternate pronuclear numeration, resulting in 16 ongoing pregnancies and 32 healthy live births, rates that match those typically observed with normally fertilized 2PN zygotes (>60%). Conclusions: A surprising number of blastocysts that were identified to have alternate pronuclear numeration at fertilization check on day 1 of embryo development were actually determined to be diploid with normal fertilization after molecular analysis. Accurate identification of haploid and tripoid zygotes is critical to prevent implantation failure and pregnancy loss and allows for the identification of all euploid embryos in a cohort, which has the potential to increase cumulative live birth rates for infertility patients. Full article

Background/Objectives: To assess the ploidy status of embryos via preimplantation genetic testing for aneuploidy (PGT-A), a biopsy of trophectoderm (TE) cells can be performed. However, this approach is considered invasive, and therefore the aim of this study was to identify the optimal sample type and sampling day for non-invasive or minimally invasive PGT-A (ni/miPGT-A) in terms of data quality and concordance rates with TE biopsies derived from the same embryos. Methods: This study was performed using 239 embryo cultures. After optimization using 96 embryos, non-invasive spent culture media (SCM) and a minimally invasive combination of blastocoel fluid and SCM (BF+SCM), along with the corresponding TE samples, were collected from 143 embryos cultured for 5 days (n = 70) or 6 days (n = 73), and all were subjected to ni/miPGT-A with whole-genome amplification followed by next-generation sequencing. Results: The amplification failure rate was lower for SCM samples than for BF+SCM (SCM: 0.7%, 1/143 vs. BF+SCM: 7.7%, 11/143; p = 0.005). The rate of ploidy concordance with TE was significantly higher for SCM samples than for BF+SCM samples (SCM: 83.7%, 118/141 vs. BF+SCM: 58%, 76/131; p < 0.001). Among SCM samples, concordance rates were higher for samples derived from embryos cultured for 6 days (87.5%, 63/72) than for 5 days (79.7%, 55/69). In the embryos cultured for 6 days, discordant cases included five (6.9%) SCM samples with falsely negative (euploid) results that were deemed to be mosaic according to TE and four (5.6%) samples falsely found to be aneuploid. Conclusions: SCM samples derived from embryos cultured for 6 days can be applied in niPGT-A with subsequent verification of aneuploid samples using TE biopsy. Full article

The evolution of preimplantation genetic testing for aneuploidy (PGT-A) techniques has been crucial in assisted reproductive technologies (ARTs), improving embryo selection and increasing success rates in in vitro fertilization (IVF) treatments. Techniques ranging from fluorescence in situ hybridization (FISH) to next-generation sequencing (NGS) have relied on cellular material extraction through biopsies of blastomeres at the cleavage stage on day three or from trophectoderm (TE) cells of the blastocyst. However, this has raised concerns about its potential impact on embryo development. As a result, there has been growing interest in developing non-invasive techniques for detecting aneuploidies, such as the analysis of blastocoel fluid (BF), spent culture medium (SCM), and artificial intelligence (AI) models. Non-invasive methods represent a promising advancement in PGT-A, offering the ability to detect aneuploidies without compromising embryo viability. This article reviews the evolution and principles of PGT-A, analyzing both traditional techniques and emerging non-invasive approaches, while highlighting the advantages and challenges associated with these methodologies. Furthermore, it explores the transformative potential of these innovations, which could optimize genetic screening and significantly improve clinical outcomes in the field of assisted reproduction. Full article

Background: To investigate prenatal ultrasound findings and the chromosomal outcomes of mosaic embryo transfer. Methods: This retrospective study was conducted on pregnant women who underwent mosaic embryo transfer following blastocyst-stage preimplantation genetic testing for aneuploidy (PGT-A) at CHA Gangnam Medical Center from January 2021 to July 2024. Trophectoderm biopsy specimens were collected using standard protocols, and next-generation sequencing profiles were defined as mosaics when displaying copy number counts in the 20–80% range. The results of the PGT-A, the amniocentesis results, the findings of prenatal ultrasounds, and the pregnancy outcomes were analyzed. Results: A total of 88 mosaic embryos were transferred, of which 77 embryos were successfully implanted. Sixty-seven embryo-maintained pregnancies went beyond 11 weeks (87.0%), all among 58 patients with singleton pregnancies. The chaotic subtype showed the lowest ongoing pregnancy rate, and high-level mosaicism was less frequent in the ongoing group, compared to the total study group and the successful implantation group. Amniocentesis was performed on 33 mothers (56.9%), revealing two cases with abnormal findings that did not correlate with the PGT-A results. Two cases showed abnormalities in the second trimester detailed ultrasound, and both subsequently demonstrated normal findings in the third trimester and after birth. The average gestational age at birth was 38.4 weeks, and the average birth weight was 3313 g. No congenital anomalies were detected in 16 postnatal cases. Conclusions: Our study indicated that mosaic embryos can develop into euploid healthy infants with various levels or types of mosaicism, although the postnatal follow-up data are limited. This study is invaluable for counseling clinical results after mosaic embryo transfer, reassuring that, if patients do not have euploid embryos available, mosaic embryos can also be a viable option for transfer. Full article

Pre-implantation genetic testing (PGT) is a crucial process for selecting embryos created through assisted reproductive technology (ART). Couples with chromosomal rearrangements, infertility, recurrent miscarriages, advanced maternal age, known single-gene disorders, a family history of genetic conditions, previously affected pregnancies, poor embryo quality, or congenital anomalies may be candidates for PGT. Preimplantation genetic testing for aneuploidies (PGT-A) enables the selection and transfer of euploid embryos, significantly enhancing implantation rates in assisted reproduction. Fluorescence in situ hybridization (FISH) is the preferred method for analyzing biopsied cells to identify these abnormalities. While FISH is a well-established method for identifying sperm aneuploidy, NGS offers a more comprehensive assessment of genetic material, potentially enhancing our understanding of male infertility. Chromosomal abnormalities, arising during meiosis, can lead to aneuploid sperm, which may hinder embryo implantation and increase miscarriage rates. This review provides a comparative analysis of fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) in sperm evaluations, focusing on their implications for preimplantation genetic testing. This analysis explores the strengths and limitations of FISH and NGS, aiming to elucidate their roles in improving ART outcomes and reducing the risk of genetic disorders in offspring. Ultimately, the findings will inform best practices in sperm evaluations and preimplantation genetic testing strategies. Full article