Preimplantation Genetic Testing: Where We Are Today

Haplotyping-based preimplantation genetic testing for inherited cardiovascular disease: a multidisciplinary approach

Given the high morbidity, mortality, and hereditary risk of cardiovascular diseases (CVDs), their prevention and control have garnered widespread attention and remain central to clinical research. This study aims to assess the feasibility and necessity of haplotyping-based preimplantation genetic testing for the prevention of inherited CVD. A total of 15 preimplantation genetic testing for monogenic defect (PGT-M) cycles were performed in 12 CVD families from January 2016 to July 2022. All couples were affected by CVDs and carried specific causative genes (including MYH7, MYBPC3, TTN, TPM1, LMNA, KCNQ1, FBN1 and LDLR). Among the 10 couples with adequate genetic pedigree information, we utilized the karyomapping assay to obtain single-nucleotide polymorphisms (SNPs) allele data. For the 2 couples who had no reference in their family, we used single sperm next-generation sequencing (NGS) to realize haplotype construction. Linkage analysis was performed to deduce embryonic genotype, and aneuploidy was screened simultaneously. Prenatal diagnostic testing via amniocentesis at 18-22 weeks of gestation was performed to verify the genetic conditions of transferred embryos. In total, 120 embryos were examined in this study, and the results showed that only 26.7% (32/120) were mutation-free and euploid-confirmed embryos. Additionally, for female CVD patients, we convened a multidisciplinary team (MDT) to advise the couple on their fertility concerns and management measures during pregnancy and delivery. With our cooperation, 10 couples successfully obtained healthy babies not carrying the pathogenic mutations. The results of prenatal diagnostics were consistent with the results of PGT-M. Our study demonstrates that PGT-M based on haplotype analysis is reliable and necessary for the prevention of inherited CVDs. It also highlights the important value of multidisciplinary collaboration for CVD prevention and treatment. Inherited cardiovascular diseases (CVDs) present as a huge challenge for modern medical and health systems. Hundreds of genetic variants have been reported to cause CVD and the number of people with the disease is enormous and still on the rise globally. Here we recruited twelve couples suffering from inherited CVD and provided them with effective pre-implantation genetic testing for monogenic defect (PGT-M) strategy to avoid the occurrence of genetic defects in the offspring. Specifically, after embryo biopsy, we utilized karyomapping assay (for 10 couples with a family history) or next-generation sequencing (NGS) (for 2 couples having no reference in their pedigree) to obtain single-nucleotide polymorphisms (SNPs) allele data and then performed linkage analysis to deduce embryonic genotype. A total of 120 embryos from 15 PGT-M cycles were examined and 12 variants in 8 genes linked to inherited CVD were identified. Thirty-two mutation-free and euploid confirmed embryos were considered suitable for embryo transfer. Besides, for female CVD patients, we called up a multidisciplinary team (MDT) advising the couple on their fertility concerns and management measures of pregnancy and delivery. With our cooperation, 10 couples successfully obtain healthy babies not carrying the pathogenic mutations. Our study further validated the reliability of PGT-M utilizing linkage analysis as a means to prevent the transmission of genetic disorders to future generations, and offered valuable insights for multidisciplinary clinical practices on CVD.

One-step warming of vitrified human cleavage and blastocyst stage embryos does not adversely impact embryo survivability and subsequent developmental potential

STUDY QUESTION

Does one-step warming (OW), a simplified embryo warming protocol, adversely affect survival and developmental potential in vitrified cleavage or blastocyst stage embryos compared to standard multi-step warming (SW)?

SUMMARY ANSWER

OW showed no detrimental effects on survival and developmental potential compared to SW in cleavage and blastocyst stage embryos.

WHAT IS KNOWN ALREADY

While standard embryo warming protocols involve a multi-step procedure using a stepwise osmotic solution to avoid a rapid influx of water into the embryo, recent studies suggest that eliminating the stepwise warming process does not reduce embryo survival and embryo transfer outcomes. However, previous reports have focused primarily on pregnancy rates, and a more detailed analysis of the effects of rapid osmotic pressure changes on embryos is necessary to standardize the protocol.

STUDY DESIGN, SIZE, DURATION

This preliminary study includes donated 377 vitrified human embryos (177 cleavage and 200 blastocyst stage) from 210 patients approved for discard at the patient's consent. The embryos were randomly allocated and warmed using either SW or OW protocols. In the SW protocol, embryos were rinsed with a stepwise osmotic solution (thawing, dilution, and washing solutions), and the process was completed with a 13-min warming period. In the OW protocol, embryos were only rinsed in a single solution (thawing solution) for 1 min.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Post-warming embryos were cultured using a time-lapse incubator. Survival rate and developmental potential, including the occurrence of abnormal morphokinetics and the time required for blastocyst formation after warming of cleavage stage embryos, were compared between SW and OW. Embryos that developed into the blastocyst stage were morphologically evaluated. In the warming of blastocyst stage embryos, the survival rate was determined by the presence of blastocoel expansion, and the proportion of full re-expanded blastocysts was observed at 3- and 24-h post-warming. An in vitro adhesion assay was also performed on blastocysts after culture, and adhesion rate and outgrowth area were measured 24, 48, and 72 h after culture with fibronectin-precoated dishes.

MAIN RESULTS AND THE ROLE OF CHANCE

OW did not negatively impact survival rates in either cleavage (100% in both OW and SW groups) or blastocyst stage embryos (99% in both groups). Cleavage stage embryos warmed by OW had superior or comparable rates of morulation (96 vs 85%, P = 0.0387), blastulation (78 vs 73%, P = 0.4044), full-blastocyst formation (60 vs 53%, P = 0.3196), and expanded-blastocyst formation (56 vs 49%, P = 0.4056) compared to those warmed by SW. Time-lapse monitoring analysis revealed that the frequency of collapses was reduced in OW (30 vs 50%, P = 0.0410). Additionally, all other abnormal morphokinetics were equivalent between OW and SW (P > 0.05); moreover, the time required for blastocyst formation (P > 0.05) and the morphological quality after development into the blastocyst stage (P > 0.05) were not significantly different between OW and SW. In warming of blastocyst stage embryos, the time required for full re-expansion was longer with OW (3.20 ± 3.03 h vs 2.14 ± 2.17 h, P = 0.0008), but there was no significant difference in the proportion of full re-expanded blastocysts at 3- (67 vs 75%, P = 0.2417) and 24-h (98 vs 97%, P = 1.0000) post-warming. The in vitro adhesion assay showed no significant differences in adhesion rate and outgrowth area at all observation points (P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

This study was carried out as a preliminary trial using discarded embryos, which limited the number of embryos analyzed. Additionally, the impact on embryo transfer outcomes, such as clinical pregnancy and livebirth rates, remains unclear.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that OW is a safe and efficient alternative to SW protocols and may improve the efficiency of IVF laboratory workflow without impairing embryo potentials.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was obtained for this study. The authors have no conflicts of interest to declare related to this study.

TRIAL REGISTRATION NUMBER

N/A.

Employment of a Newly Defined In Vitro Fertilization Protocol to Determine the Cytoskeletal Machinery, DNA Damage, and Subsequent DNA Repair Resulting from Endocrine Disruption by Hexavalent Chromium in Rat Metaphase II Oocytes

These protocols describe a detailed method to determine the DNA damage and F-actin and microtubule defects of metaphase II oocytes caused by hexavalent chromium, Cr(VI), an endocrine disrupting chemical (EDC). The protocol provides systematic steps to determine protein expression encoded by pluripotency proteins such as Oct4, Nanog, and Cdx2 during early embryonic development. Occupational or environmental exposure to EDCs has significantly increased infertility in both men and women. The urinary concentration of the EDC bisphenol A in patients undergoing in vitro fertilization (IVF) is directly related to decreased implantation rates and the number of metaphase II oocytes recovered. This protocol outlines crucial steps in assessing the structure of F-actin and microtubules, DNA damage, and repair mechanisms in metaphase II oocytes as well as pluripotency protein markers of early-stage embryos. IVF techniques to achieve fertility goals in both humans and animals are of paramount importance. The interplay between F-actin and microtubules is crucial for bipolar spindle assembly and correct partitioning of the nuclear genome in mammalian oocyte meiosis. EDCs induce DNA damage and impair DNA repair mechanisms, compromising oocyte quality. In human IVF, this results in failure to implant, early miscarriage, and live births with congenital disorders, thus decreasing success rates and increasing poor outcomes. The application of IVF protocols in rats to understand EDC-mediated defects in the cytoskeletal network of metaphase II oocytes is not well established. We present a newly defined rat IVF protocol and demonstrate outcomes using these protocols to determine the adverse effects of Cr(VI) on metaphase II oocytes. Basic Protocol 1 includes steps to superovulate rats, dissect ampullae, retrieve oocytes/eggs, perform immunofluorescence staining of cytoskeletal machinery (microtubules and F-actin), and assess expression of the DNA double-strand break marker γ-H2AX and the DNA repair protein RAD51 in control and Cr(VI)-exposed rats. Basic Protocol 2 describes methods for detecting the pluripotency proteins Oct4, Nanog, and Cdx2 during early embryonic development in control rats. © 2024 Wiley Periodicals LLC. Basic Protocol 1: In vivo EDC treatment of rats and immunostaining of treated oocytes Basic Protocol 2: In vitro fertilization and immunostaining of early-stage embryos.

Automatic ploidy prediction and quality assessment of human blastocysts using time-lapse imaging

Assessing fertilized human embryos is crucial for in vitro fertilization, a task being revolutionized by artificial intelligence. Existing models used for embryo quality assessment and ploidy detection could be significantly improved by effectively utilizing time-lapse imaging to identify critical developmental time points for maximizing prediction accuracy. Addressing this, we develop and compare various embryo ploidy status prediction models across distinct embryo development stages. We present BELA, a state-of-the-art ploidy prediction model that surpasses previous image- and video-based models without necessitating input from embryologists. BELA uses multitask learning to predict quality scores that are thereafter used to predict ploidy status. By achieving an area under the receiver operating characteristic curve of 0.76 for discriminating between euploidy and aneuploidy embryos on the Weill Cornell dataset, BELA matches the performance of models trained on embryologists' manual scores. While not a replacement for preimplantation genetic testing for aneuploidy, BELA exemplifies how such models can streamline the embryo evaluation process.

Non-Obstructive Azoospermia and Intracytoplasmic Sperm Injection: Unveiling the Chances of Success and Possible Consequences for Offspring

Non-obstructive azoospermia (NOA) is found in up to 15% of infertile men. While several causes for NOA have been identified, the exact etiology remains unknown in many patients. Advances in assisted reproductive technology, including intracytoplasmic sperm injection (ICSI) and testicular sperm retrieval, have provided hope for these patients. This review summarizes the chances of success with ICSI for NOA patients and examines preoperative factors and laboratory techniques associated with positive outcomes. Furthermore, we reviewed possible consequences for offspring by the use of ICSI with testicular sperm retrieved from NOA patients and the interventions that could potentially mitigate risks. Testicular sperm retrieved from NOA patients may exhibit increased chromosomal abnormalities, and although lower fertilization and pregnancy rates are reported in NOA patients compared to other forms of infertility, the available evidence does not suggest a significant increase in miscarriage rate, congenital malformation, or developmental delay in their offspring compared to the offspring of patients with less severe forms of infertility or the offspring of fertile men. However, due to limited data, NOA patients should receive specialized reproductive care and personalized management. Counseling of NOA patients is essential before initiating any fertility enhancement treatment not only to mitigate health risks associated with NOA but also to enhance the chances of successful outcomes and minimize possible risks to the offspring.

Development and assessment of a knowledge, attitude, and practice (KAP) questionnaire for genetic counselees with preimplantation genetic testing (PGT) indications

Background

Preimplantation genetic testing (PGT) can reduce the risk of familial genetic diseases, chromosome abnormalities, and recurrent abortions. It is unclear whether genetic counselees with PGT indications understand and accept the implications of PGT. A well-developed and validated tool is needed to evaluate the knowledge, attitude, and practice (KAP) levels of genetic counselees with PGT indications. The purpose of this study was to develop and validate a PGT KAP questionnaire (PGT-KAP-Q) for genetic counselees with PGT indications.

Methods

First, we established an item pool based on a literature review and qualitative interviews. Second, we developed the PGT-KAP-Q using the Delphi method. Third, we evaluated the quality of the questionnaire using item analysis and psychometric evaluation. The item analysis included extreme value comparison, application of the correlation and Cronbach's alpha (α) coefficient methods, and factor analysis. We also evaluated the content and structural validity of the questionnaire, as well as the internal consistency, test-retest reliability, and split-half reliability.

Findings

After the literature review and interviews, and based on three rounds of expert consultations, we formed a 43-item questionnaire. In the validity analysis, the item's content validity index (I-CVI) and the average scale level CVI (S-CVI/Ave) values (>0.78 and >0.95, respectively) confirmed the questionnaire's content validity. Exploratory factor analysis showed that all 43 items had strong factor loadings (>0.4), and the three factors of the PGT-KAP-Q explained 51.97 % of the total variance. The Cronbach's α coefficient for the questionnaire was 0.95 (p < 0.05), the split-half reliability was 0.76 (p < 0.05) and the test-retest reliability coefficient was 0.78 (p < 0.05).

Interpretation

The 43-item PGT-KAP-Q for genetic counselees with PGT indications is reliable and valid. It contains a moderate number of items, is easy for patients to understand and accept, and can be used for clinical research and applications.

Morphological quality on Day 3 affects the pregnancy outcomes of low-quality euploid blastocysts: a retrospective cohort study

STUDY QUESTION

Does the morphological quality on Day 3 influence the pregnancy outcomes of euploid blastocysts?

SUMMARY ANSWER

The morphological quality on Day 3 affects the clinical pregnancy rate (CPR) and live birth rate (LBR) of low-quality euploid blastocysts.

WHAT IS KNOWN ALREADY

The morphological grading of Day 3 embryos affects the pregnancy outcome of cleavage-stage embryos and is an excellent indicator to predict embryo development potential. However, it is still unclear whether morphological quality on Day 3 is associated with pregnancy outcomes of the euploid blastocyst.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study comprised 1275 patients who received single euploid blastocyst transfer between January 2016 and August 2021 at a tertiary teaching hospital.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were grouped into two groups according to the morphological grading on Day 3 of transferred blastocysts: high-quality (HQ, including Grades I and II) Day 3 embryos and low-quality (LQ, Grade III) Day 3 embryos. The primary outcomes were CPR and LBR. Interactions of development days (Day 5 and Day 6) and morphological quality (high- and low-quality) of blastocysts with morphological quality of Day 3 embryos on pregnancy outcomes were tested in the stratified analysis and logistic regression models. The multivariate logistic regression analysis was conducted to investigate the independent effect of the morphological quality of Day 3 embryos on pregnancy outcomes after adjusting for potentially confounding factors.

MAIN RESULTS AND THE ROLE OF CHANCE

The CPR and LBR of the HQ Day 3 embryos group were statistically higher than those of the LQ Day 3 embryos group (CPR: 59.73% versus 49.70%, respectively, P = 0.015; LBR: 49.73% versus 41.21%, respectively, P = 0.041). The development days of blastocysts did not exhibit a multiplicative interaction with the morphological quality of Day 3 embryos on the CPR (P for interaction = 0.648) and LBR (P for interaction = 0.925). The morphological quality of blastocysts exhibits a multiplicative interaction with the morphological quality of Day 3 embryos on the CPR (P for interaction = 0.020) and LBR (P for interaction = 0.012). After adjusting for potential confounders, the HQ Day 3 embryo group was positively associated with the CPR (adjusted odds ratio (aOR): 2.10, 95% CI: 1.31-3.36, P = 0.002) and LBR (aOR: 1.97, 95% CI: 1.20-3.25, P = 0.008) of LQ blastocysts. However, the morphological quality on Day 3 was not significantly associated with the CPR (aOR: 0.95, 95% CI: 0.58-1.55, P = 0.835) and LBR (aOR: 0.86, 95% CI: 0.53-1.40, P = 0.550) of HQ blastocysts.

LIMITATIONS, REASONS FOR CAUTION

Selection and confounding bias introduced by the retrospective design cannot be completely eliminated in this study, although multivariable logistic analysis was conducted to adjust for potential confounders. Also, some subgroups had small sample sizes, which may reduce statistical power. Moreover, participants in our study only received single euploid blastocyst transfer, and whether the results could apply to blastocysts with unknown ploidy status is unclear.

WIDER IMPLICATIONS OF THE FINDINGS

This study found that the morphological quality on Day 3 was significantly associated with the CPR and LBR of LQ blastocysts; Therefore, when only LQ euploid blastocysts are available for transfer, blastocysts derived from HQ Day 3 embryos are recommended.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was obtained. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Concurrent Preimplantation Genetic Testing and Competence Assessment of Human Embryos by Transcriptome Sequencing

Preimplantation genetic testing (PGT) can minimize the risk of birth defects. However, the accuracy and applicability of routine PGT is confounded by uneven genome coverage and high allele drop-out rate from existing single-cell whole genome amplification methods. Here, a method to diagnose genetic mutations and concurrently evaluate embryo competence by leveraging the abundant mRNA transcript copies present in trophectoderm cells is developed. The feasibility of the method is confirmed with 19 donated blastocysts. Next, the method is applied to 82 embryos from 26 families with monogenic defects for simultaneous mutation detection and competence assessment. The accuracy rate of direct mutation detection is up to 95%, which is significantly higher than DNA-based method. Meanwhile, this approach correctly predicted seven out of eight (87.5%) embryos that failed to implant. Of six embryos that are predicted to implant successfully, four met such expectations (66.7%). Notably, this method is superior at conditions for mutation detection that are challenging when using DNA-based PGT, such as when detecting pathogenic genes with a high de novo rate, multiple pseudogenes, or an abnormal expansion of CAG trinucleotide repeats. Taken together, this study establishes the feasibility of an RNA-based PGT that is also informative for assessing implantation competence.

Hysteroscopic Endometrial Fundal Incision versus Hysteroscopy Only in Oocyte Recipients: A Randomized Controlled Trial Assessing The Reproductive Outcomes

BACKGROUND

Endometrial scratching (ES) remains controversial regarding its potential effectiveness in improving pregnancy rates. The objective of the present study was to assess the impact of endometrial fundal incision (EFI) during hysteroscopy on reproductive outcomes in a population of oocyte recipients.

MATERIALS AND METHODS

A randomized controlled trial was conducted between 2020 and 2023 at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki and "Assisting Nature Centre of Reproduction and Genetics". The study population consisted of women who underwent hysteroscopy randomly assigned in a 1:1 ratio to either EFI (one to three months before embryotransfer with donor oocytes) or no intervention throughout office hysteroscopy. Clinical pregnancy and live birth rates were the primary outcomes.

RESULTS

After the exclusion of patients with intraoperative diagnosed endometrial pathology, a total of 124 women underwent randomization. The pregnancy test was positive in 79% (n=49/62) of the women in the EFI compared to 59.7% (n=37/62) in the hysteroscopy-only group (P=0.019), while the live birth rates did not differ between the two groups (58.1%, n=36/62 vs. 51.6%, n=32/62, P=0.470).

CONCLUSION

EFI during hysteroscopy seems to improve pregnancy rates in oocyte recipients without intrauterine pathology, while live birth rates are not affected by the EFI. These results should be interpreted with caution before the implementation of EFI in the routine in vitro fertilization (IVF) practice (registration number: NCT04580056).

Expression of miRNA from spent pre-implantation embryos culture media

This study examines the expression of three microRNAs (hsa-miR-661, hsa-miR-21-5p, hsa-miR-372-5p) in spent pre-implantation embryos culture media to identify possible new non-invasive biomarkers of embryo competence, predictive of development to the blastocyst stage. A preliminary analysis on 16 patients undergoing IVF cycles was performed by collecting and stored spent culture media on the fifth/sixth day of embryo culture. Expression of miRNAs was evaluated according to the embryos' fate: 1) NE/DG: non-evolved or degenerate embryos; 2) BLOK: embryos developed to the blastocyst stage. Preliminary results revealed a higher miRNAs expression in NE/DG spent media. To elucidate the roles of these miRNAs, we employed a robust bioinformatics pipeline involving: 1) in-silico miRNA Target Prediction using RNAHybrid, which identified the most-likely gene targets; 2) Construction of a Protein-Protein Interaction network via GeneMania, linking genes with significant biological correlations; 3) application of modularity-based clustering with the gLay app in Cytoscape, resulting in three size-adapted subnets for focused analysis; 4) Enrichment Analysis to discern the biological pathways influenced by the miRNAs. Our bioinformatics analysis revealed that hsa-miR-661 was closely associated with pathways regulating cell shape and morphogenesis of the epithelial sheet. These data suggest the potential use of certain miRNAs to identify embryos with a higher likelihood of developing to the blastocyst stage. Further analysis will be necessary to explore the reproducibility of these findings and to understand if miRNAs here investigated can be used as biomarkers for embryo selection before implantation into the uterus or if they may be reliable predictors of IVF outcome.

A novel non-invasive embryo evaluation method (NICS-Timelapse) with enhanced predictive precision and clinical impact

The selection of the finest possible embryo in in-vitro fertilization (IVF) was crucial and revolutionary, particularly when just one embryo is transplanted to lessen the possibility of multiple pregnancies. However, practical usefulness of currently used methodologies may be constrained. Here, we established a novel non-invasive embryo evaluation method that combines non-invasive chromosomal screening (NICS) and Timelapse system along with artificial intelligence algorithms. With an area under the curve (AUC) of 0.94 and an accuracy of 0.88, the NICS-Timelapse model was able to predict blastocyst euploidy. The performance of the model was further evaluated using 75 patients in various clinical settings. The clinical pregnancy and live birth rates of embryos predicted by the NICS-Timelapse model, showing that embryos with higher euploid probabilities were associated with higher clinical pregnancy and live birth rates. These results demonstrated the NICS-Timelapse model's significantly wider application in clinical IVF due to its excellent accuracy and noninvasiveness.

Aneuploidy detection in pooled polar bodies using rapid nanopore sequencing

PURPOSE

Various screening techniques have been developed for preimplantation genetic testing for aneuploidy (PGT-A) to reduce implantation failure and miscarriages in women undergoing in vitro fertilisation (IVF) treatment. Among these methods, the Oxford nanopore technology (ONT) has already been tested in several tissues. However, no studies have applied ONT to polar bodies, a cellular material that is less restrictively regulated for PGT-A in some countries.

METHODS

We performed rapid short nanopore sequencing on pooled first and second polar bodies of 102 oocytes from women undergoing IVF treatment to screen for aneuploidy. An automated analysis pipeline was developed with the expectation of three chromatids per chromosome. The results were compared to those obtained by array-based comparative genomic hybridisation (aCGH).

RESULTS

ONT and aCGH were consistent for 96% (98/102) of sample ploidy classification. Of those samples, 36 were classified as euploid, while 62 were classified as aneuploid. The four discordant samples were assessed as euploid using aCGH but classified as aneuploid using ONT. The concordance of the ploidy classification (euploid, gain, or loss) per chromosome was 92.5% (2169 of 2346 of analysed chromosomes) using aCGH and ONT and increased to 97.7% (2113/2162) without the eight samples assessed as highly complex aneuploid using ONT.

CONCLUSION

The automated detection of the ploidy classification per chromosome and shorter duplications or deletions depending on the sequencing depth demonstrates an advantage of the ONT method over standard, commercial aCGH methods, which do not consider the presence of three chromatids in pooled polar bodies.

The mosaic embryo: what it means for the doctor and the patient

INTRODUCTION

Mosaic embryos are embryos that on preimplantation genetic analysis are found to be composed of euploid and aneuploid cells. Although most of these embryos do not implant when transferred into the uterus following IVF treatment, some may implant and are capable of giving rise to babies.

EVIDENCE ACQUISITION

There is currently an increasing number of reports of live births following the transfer of mosaic embryos. Compared to euploid, mosaic embryos have lower implantation rates and higher rates of miscarriage, and occasionally aneuploid component persists. However, their outcome is better than that obtained after the transfer of embryos consisting entirely of aneuploid cells. After implantation, the ability to develop into a full-term pregnancy is influenced by the amount and type of chromosomal mosaicism present in a mosaic embryo. Nowadays many experts in the reproductive field consider mosaic transfers as an option when no euploid embryos are available. Genetic counseling is an important part of educating patients about the likelihood of having a pregnancy with healthy baby but also on the risk that mosaicism could persist and result in liveborn with chromosomal abnormality. Each situation needs to be assessed on a case-by-case basis and counseled accordingly.

EVIDENCE SYNTHESIS

So far, the transfers of 2155 mosaic embryos have been documented and 440 live births resulting in healthy babies have been reported. In addition, in the literature to date, there are 6 cases in which embryonic mosaicism persisted.

CONCLUSIONS

In conclusion, the available data indicate that mosaic embryos have the potential to implant and develop into healthy babies, albeit with lower success rates than euploids. Further clinical outcomes should be collected to better establish a refined ranking of embryos to transfer.

Trophectoderm biopsy of blastocysts following IVF and embryo culture increases epigenetic dysregulation in a mouse model

STUDY QUESTION

Does trophectoderm biopsy (TEBx) of blastocysts for preimplantation genetic testing in the clinic affect normal placental and embryo development and offspring metabolic outcomes in a mouse model?

SUMMARY ANSWER

TEBx impacts placental and embryonic health during early development, with some alterations resolving and others worsening later in development and triggering metabolic changes in adult offspring.

WHAT IS KNOWN ALREADY

Previous studies have not assessed the epigenetic and morphological impacts of TEBx either in human populations or in animal models.

STUDY DESIGN, SIZE, DURATION

We employed a mouse model to identify the effects of TEBx during IVF. Three groups were assessed: naturally conceived (Naturals), IVF, and IVF + TEBx, at two developmental timepoints: embryonic day (E)12.5 (n = 40/Naturals, n = 36/IVF, and n = 36/IVF + TEBx) and E18.5 (n = 42/Naturals, n = 30/IVF, and n = 35/IVF + TEBx). Additionally, to mimic clinical practice, we assessed a fourth group: IVF + TEBx + Vitrification (Vit) at E12.5 (n = 29) that combines TEBx and vitrification. To assess the effect of TEBx in offspring health, we characterized a 12-week-old cohort (n = 24/Naturals, n = 25/IVF and n = 25/IVF + TEBx).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our mouse model used CF-1 females as egg donors and SJL/B6 males as sperm donors. IVF, TEBx, and vitrification were performed using standardized methods. Placenta morphology was evaluated by hematoxylin-eosin staining, in situ hybridization using Tpbpa as a junctional zone marker and immunohistochemistry using CD34 fetal endothelial cell markers. For molecular analysis of placentas and embryos, DNA methylation was analyzed using pyrosequencing, luminometric methylation assay, and chip array technology. Expression patterns were ascertained by RNA sequencing. Triglycerides, total cholesterol, high-, low-, and very low-density lipoprotein, insulin, and glucose were determined in the 12-week-old cohort using commercially available kits.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed that at E12.5, IVF + TEBx had a worse outcome in terms of changes in DNA methylation and differential gene expression in placentas and whole embryos compared with IVF alone and compared with Naturals. These changes were reflected in alterations in placental morphology and blood vessel density. At E18.5, early molecular changes in fetuses were maintained or exacerbated. With respect to placentas, the molecular and morphological changes, although different compared to Naturals, were equivalent to the IVF group, except for changes in blood vessel density, which persisted. Of note is that most differences were sex specific. We conclude that TEBx has more detrimental effects in mid-gestation placental and embryonic tissues, with alterations in embryonic tissues persisting or worsening in later developmental stages compared to IVF alone, and the addition of vitrification after TEBx results in more pronounced and potentially detrimental epigenetic effects: these changes are significantly different compared to Naturals. Finally, we observed that 12-week IVF + TEBx offspring, regardless of sex, showed higher glucose, insulin, triglycerides, lower total cholesterol, and lower high-density lipoprotein compared to IVF and Naturals, with only males having higher body weight compared to IVF and Naturals. Our findings in a mouse model additionally support the need for more studies to assess the impact of new procedures in ART to ensure healthy pregnancies and offspring outcomes.

LARGE SCALE DATA

Data reported in this work have been deposited in the NCBI Gene Expression Omnibus under accession number GSE225318.

LIMITATIONS, REASONS FOR CAUTION

This study was performed using a mouse model that mimics many clinical IVF procedures and outcomes observed in humans, where studies on early embryos are not possible.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the importance of assaying new procedures used in ART to assess their impact on placenta and embryo development, and offspring metabolic outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by a National Centers for Translational Research in Reproduction and Infertility grant P50 HD068157-06A1 (M.S.B., C.C., M.M.), Ruth L. Kirschstein National Service Award Individual Postdoctoral Fellowship F32 HD107914 (E.A.R.-C.) and F32 HD089623 (L.A.V.), and National Institutes of Health Training program in Cell and Molecular Biology T32 GM007229 (C.N.H.). No conflict of interest.

Preimplantation genetic testing: A remarkable history of pioneering, technical challenges, innovations, and ethical considerations

Preimplantation genetic testing (PGT) has emerged as a powerful companion to assisted reproduction technologies. The origins and history of PGT are reviewed here, along with descriptions of advances in molecular assays and sampling methods, their capabilities, and their applications in preventing genetic diseases and enhancing pregnancy outcomes. Additionally, the potential for increasing accuracy and genome coverage is considered, as well as some of the emerging ethical and legislative considerations related to the expanding capabilities of PGT.

Current Applications and Controversies in Preimplantation Genetic Testing for Aneuploidies (PGT-A) in In Vitro Fertilization

Preimplantation genetic testing for aneuploidy (PGT-A) has evolved over recent years, including improvements in embryo culture, biopsy, transfer, and genetic testing. The application of new comprehensive chromosome screening analysis has improved the accuracy in determining the chromosomal status of the analyzed sample, but it has brought new challenges such as the management of partial aneuploidies and mosaicisms. For the past two decades, PGT-A has been involved in a controversy regarding its efficiency in improving IVF outcomes, despite its widespread worldwide implementation. Understanding the impact of embryo aneuploidy in IVF (in vitro fertilization) should theoretically allow improving reproductive outcomes. This review of the literature aims to describe the impact of aneuploidy in human reproduction and how PGT-A was introduced to overcome this obstacle in IVF (in vitro fertilization). The article will try to analyze and summarize the evolution of the PGT-A in the recent years, and its current applications and limitations, as well as the controversy it generates. Conflicting published data could indicate the lacking value of a single biopsied sample to determine embryo chromosomal status and/or the lack of standardized methods for embryo culture and management and genetic analysis among other factors. It has to be considered that PGT-A may not be a universal test to improve the reproductive potential in IVF patients, rather each clinic should evaluate the efficacy of PGT-A in their IVF program based on their population, skills, and limitations.

From oocytes to a live birth: Are we improving the biological efficiency?

OBJECTIVE(S)

The objectives of our study were to investigate the live birth rate (LBR) per oocyte retrieved during in vitro fertilization, in patients who had used all their embryos and to extrapolate the LBR in patients with remaining frozen embryos by calculating the expected LBR from these embryos.

DESIGN

A retrospective cohort study.

SETTING

A single academically affiliated fertility clinic.

PATIENT(S)

Autologous in vitro fertilization cycles from January 2014 to December 2020. Data on the number of oocytes retrieved, number of embryos obtained and transferred (at cleavage or blastocyst-stage), use of preimplantation genetic testing for aneuploidy (PGT-A), and number of live births were obtained. The expected LBR was estimated in patients with remaining frozen embryos according to nationally reported Society for Assisted Reproductive Technology LBR data.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth rate per oocyte retrieved.

RESULT(S)

A total of 12,717 patients met the inclusion criteria and underwent a total of 20,677 oocyte retrievals which yielded a total of 248,004 oocytes and 57,268 embryos (fresh and frozen). In patients who had fully utilized all their embryos the LBR per oocyte was 2.82% (ranging from 11.3% aged <35 years to 1.2% aged >42 years). Stratification of the population based on PGT-A utilization yielded similar results (with PGT-A: 2.88% and without PGT-A: 2.79%). When stratified by the Society for Assisted Reproductive Technology age groups, the addition of PGT-A in patients aged 35-37 and 38-40 years yielded higher LBR per oocyte compared with patients who did not add PGT-A (P<.05). In patients with remaining frozen embryos who had added PGT-A, the projected LBR per oocyte was 8.34%. Use of PGT-A in patients aged <35 and 35-37 years decreased LBR per oocyte (P<.001 and P=.03, respectively) but improved LBR per oocyte in patients aged 38-40 and 41-42 years (P=.006 and P=.005, respectively). Poisson regression analysis demonstrated an age threshold of 38.5, below which PGT-A lowers LBR per oocyte compared with no PGT-A.

CONCLUSION(S)

Despite clinical and scientific advances in Assisted Reproductive Technology, with the current protocols of ovarian stimulation, the LBR per oocyte remains low reflecting a biological barrier that has yet to be overcome. Overall, the addition of PGT-A did not demonstrate improved outcomes.

Research progress and challenges of preimplantation genetic testing for polygenic diseases

Preimplantation genetic testing is an important part in assisted reproductive technology, which can block the intergenerational inheritance of a single gene or chromosomal diseases. Preimplantation genetic testing for polygenic disease risk (PGT-P) is one of the latest developments in the field. With the development of artificial intelligence and genetic detection technology, PGT-P can be used to analyze genetic material, calculate polygenic risk scores and convert these into incidence probability. Embryos with relatively low incidence probability can be screened for transfer, in order to reduce the possibility that the offspring suffers from the disease in the future. This has significant clinical and social significance. At present, PGT-P has been applied clinically and made phased progress at home and abroad. But as a developing technology, PGT-P still has some technical limitations as unstable results, environmental influences and racial differences cannot be ruled out. From the ethical perspective, if the screening indications are not strictly regulated, it is likely to cause new social problems. In this paper, we review the technical details and recent progress in PGT-P, and discuss the prospects of its future development, especially how to establish a complete and suitable screening model for Chinese population.

Preimplantation Genetic Testing for Genetic Diseases: Limits and Review of Current Literature

Preimplantation genetic testing (PGT) has emerged as a revolutionary technique in the field of reproductive medicine, allowing for the selection and transfer of healthy embryos, thus reducing the risk of transmitting genetic diseases. However, despite remarkable advancements, the implementation of PGT faces a series of limitations and challenges that require careful consideration. This review aims to foster a comprehensive reflection on the constraints of preimplantation genetic diagnosis, encouraging a broader discussion about its utility and implications. The objective is to inform and guide medical professionals, patients, and society overall in the conscious and responsible adoption of this innovative technology, taking into account its potential benefits and the ethical and practical challenges that it presents.

Assisted reproductive technology and imprinting errors: analyzing underlying mechanisms from epigenetic regulation

With the increasing maturity and widespread application of assisted reproductive technology (ART), more attention has been paid to the health outcomes of offspring following ART. It is well established that children born from ART treatment are at an increased risk of imprinting errors and imprinting disorders. The disturbances of genetic imprinting are attributed to the overlap of ART procedures and important epigenetic reprogramming events during the development of gametes and early embryos, but the detailed mechanisms are hitherto obscure. In this review, we summarized the DNA methylation-dependent and independent mechanisms that control the dynamic epigenetic regulation of imprinted genes throughout the life cycle of a mammal, including erasure, establishment, and maintenance. In addition, we systematically described the dysregulation of imprinted genes in embryos conceived through ART and discussed the corresponding underlying mechanisms according to findings in animal models. This work is conducive to evaluating and improving the safety of ART.

The status of surrogacy in China

China's birth rates hit a record low in 2021. The high demand for having children has spawned a massive market for surrogacy, which, however, is a dilemma in China involving a series of moral and legal issues under the current circumstances. First, special populations, including infertile patients, families who have lost their sole child, and homosexuals, wanted to have children, giving rise to surrogacy. Then, the development of and innovation in assisted reproductive technology allowed surrogacy to mature. A high return offsets a high risk, and consequently, an underground surrogacy market has emerged, causing various social issues for the Chinese Government, such as civil disputes, gender disproportion, crime, and the spread of disease. At the same time, surrogacy violates moral ethics, traditional Chinese culture, and the rights and interests of vulnerable groups.

The embryo non-invasive pre-implantation diagnosis era: how far are we?

Advancements in assisted reproduction (AR) methodologies have allowed significant improvements in live birth rates of women who otherwise would not be able to conceive. One of the tools that allowed this improvement is the possibility of embryo selection based on genetic status, performed via preimplantation genetic testing (PGT). Even though the widespread use of PGT from TE biopsy helped to decrease the interval from the beginning of the AR intervention to pregnancy, especially in older patients, in AR, there are still many concerns about the application of this invasive methodology in all cycles. Therefore, recently, researchers started to study the use of cell free DNA (cfDNA) released by the blastocyst in its culture medium to perform PGT, in a method called non-invasive PGT (niPGT). The development of a niPGT would bring the diagnostics power of conventional PGT, but with the advantage of being potentially less harmful to the embryo. Its implementation in clinical practice, however, is under heavy discussion since there are many unknowns about the technique, such as the origin of the cfDNA or if this genetic material is a true representative of the actual ploidy status of the embryo. Available data indicates that there is high correspondence between results observed in TE biopsies and the ones observed from cfDNA, but these results are still contradictory and highly debatable. In the present review, the advantages and disadvantages of niPGT are presented and discussed in relation to tradition TE biopsy-based PGT. Furthermore, there are also presented some other possible non-invasive tools that could be applied in the selection of the best embryo, such as quantification of other molecules as quality biomarkers, or the use artificial intelligence (AI) to identify the best embryos based on morphological and/or morphokitetic parameters.

Automatic Ploidy Prediction and Quality Assessment of Human Blastocyst Using Time-Lapse Imaging

Assessing fertilized human embryos is crucial for in vitro-fertilization (IVF), a task being revolutionized by artificial intelligence and deep learning. Existing models used for embryo quality assessment and chromosomal abnormality (ploidy) detection could be significantly improved by effectively utilizing time-lapse imaging to identify critical developmental time points for maximizing prediction accuracy. Addressing this, we developed and compared various embryo ploidy status prediction models across distinct embryo development stages. We present BELA (Blastocyst Evaluation Learning Algorithm), a state-of-the-art ploidy prediction model surpassing previous image- and video-based models, without necessitating subjective input from embryologists. BELA uses multitask learning to predict quality scores that are used downstream to predict ploidy status. By achieving an AUC of 0.76 for discriminating between euploidy and aneuploidy embryos on the Weill Cornell dataset, BELA matches the performance of models trained on embryologists' manual scores. While not a replacement for preimplantation genetic testing for aneuploidy (PGT-A), BELA exemplifies how such models can streamline the embryo evaluation process, reducing time and effort required by embryologists.

Technical Problems and Ethical Concerns Regarding Gene Editing in Human Germlines and Embryos

The Article Abstract is not Available.

Pregnancy and neonatal outcomes of monozygotic twins resulting from assisted reproductive technology: a 10-year retrospective study

BACKGROUND

Monozygotic twins (MZTs) are associated with high risks of maternal and fetal complications. Even with the widely used elective single embryo transfer (SET), the risk of MZTs following assisted reproductive technology (ART) treatments remains. However, most studies of MZTs focused on the relevant etiology, with few studies describing pregnancy and neonatal outcomes.

METHODS

This retrospective cohort study included 19,081 SET cycles resulting from in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), preimplantation genetic testing (PGT) and testicular sperm aspiration (TESA) performed between January 2010 and July 2020 in a single university-based center. A total of 187 MZTs were included in this investigation. The main outcome measures were the incidence, pregnancy and neonatal outcomes of MZTs. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy loss.

RESULTS

The overall rate of MZTs from ART treatment in SET cycles was 0.98%. No significant difference was found in the incidence of MZTs among the four groups (p = 0.259). The live birth rate of MZTs in the ICSI group (88.5%) was significantly more favorable than in the IVF, PGT and TESA groups (60.5%, 77.2% and 80%, respectively). IVF resulted in a significantly increased risk of pregnancy loss (39.4%) and early miscarriage (29.5%) in MZT pregnancies compared to ICSI (11.4%, 8.5%), PGT (22.7%, 16.6%) and TESA (20%, 13.3%). The total rate of twin-to-twin transfusion syndrome (TTTS) in MZTs was 2.7% (5/187); however, the TESA group had the highest rate at 20% and was significantly higher than the PGT group (p = 0.005). The four ART groups had no significant effect on the occurrence of congenital abnormalities or other neonatal outcomes in newborns from MZT pregnancies. Multivariate logistic regression analysis revealed that infertility duration, cause of infertility, the total dose of Gn used, history of miscarriages, and the number of miscarriages were not related to the risk of pregnancy loss (p > 0.05).

CONCLUSIONS

The rate of MZTs was similar among the four ART groups. The pregnancy loss and the early miscarriage rate of MZTs was increased in IVF patients. Neither the cause of infertility nor the history of miscarriage was correlated with the risk of pregnancy loss. MZTs in the TESA group had a higher risk of TTTS, placental effects influenced by sperm and paternally expressed genes may play a role. However, due to the small total number, studies with larger sample sizes are still needed to validate these result. Pregnancy and neonatal outcomes of MZTs after PGT treatment seem to be reassuring but the duration of the study was short, and long-term follow-up of the children is needed.

Microbiological and Cytokine Profiling of Menstrual Blood for the Assessment of Endometrial Receptivity: A Pilot Study

Endometrial receptivity (ER) is a key factor required for the successful implantation of the embryo. However, the evaluation of ER is challenging, as a nondisruptive sampling of endometrial biomaterial by conventional methods is only possible outside of the embryo transfer (ET) cycle. We propose a novel approach for the assessment of ER-microbiological and cytokine profiling of menstrual blood aspirated directly from the uterine cavity at the beginning of the cryo-ET cycle. The aim of the pilot study was to evaluate its prognostic potential regarding the outcome of the in vitro fertilization procedure. Samples collected from a cohort of 42 patients undergoing cryo-ET were analyzed by a multiplex immunoassay (48 various cytokines, chemokines, and growth factors) and a real-time PCR assay (28 relevant microbial taxa and 3 members of the Herpesviridae family). Significant differences between groups of patients who achieved and did not achieve pregnancy were observed for G-CSF, GRO-α, IL-6, IL-9, MCP-1, M-CSF, SDF-1α, TNF-β, TRAIL, SCF, IP-10, and MIG (p < 0.05), whereas microbial profiles were not associated with the outcome of cryo-ET. It appeared that levels of IP-10 and SCGF-β were significantly lower (p < 0.05), in patients with endometriosis. Menstrual blood may provide great opportunities to noninvasively investigate various parameters of the endometrium.

Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies

Retinitis pigmentosa (RP) comprises a group of inherited retinal dystrophies characterized by the degeneration of rod photoreceptors, followed by the degeneration of cone photoreceptors. As a result of photoreceptor degeneration, affected individuals experience gradual loss of visual function, with primary symptoms of progressive nyctalopia, constricted visual fields and, ultimately, central vision loss. The onset, severity and clinical course of RP shows great variability and unpredictability, with most patients already experiencing some degree of visual disability in childhood. While RP is currently untreatable for the majority of patients, significant efforts have been made in the development of genetic therapies, which offer new hope for treatment for patients affected by inherited retinal dystrophies. In this exciting era of emerging gene therapies, it remains imperative to continue supporting patients with RP using all available options to manage their condition. Patients with RP experience a wide variety of physical, mental and social-emotional difficulties during their lifetime, of which some require timely intervention. This review aims to familiarize readers with clinical management options that are currently available for patients with RP.

Does PGT-A affect cumulative live birth rate?

PURPOSE OF REVIEW

Preimplantation genetic testing for the purpose of aneuploidy screening (PGT-A) has increased in use over the last decade.

RECENT FINDINGS

Whether PGT-A benefits all of the patients that choose to employ it has been a concern, as recent studies have highlighted a potential decrease in cumulative live birth rate (CLBR) for younger patients undergoing embryo transfer. However, there are limitations to many of these studies and the intended benefit of PGT-A, which is to aid as a selection tool, thus increasing the live birth rate per transfer, must not be ignored.

SUMMARY

PGT-A was never intended to increase CLBR. The purpose of PGT-A is to maximize the chance at live birth per transfer while minimizing the risk of clinical miscarriage, ongoing aneuploid pregnancy and futile transfers. However, if it harms CLBR in the process that has to be taken into consideration. This review will discuss PGT-A in terms of its benefits, risks, and how it has been shown to affect the cumulative live birth rate within in-vitro fertilization cycles.

Preimplantation Genetic Testing for Aneuploidy (PGT-A) Reveals High Levels of Chromosomal Errors in In Vivo-Derived Pig Embryos, with an Increased Incidence When Produced In Vitro

Preimplantation genetic testing for aneuploidy (PGT-A) is widespread, but controversial, in humans and improves pregnancy and live birth rates in cattle. In pigs, it presents a possible solution to improve in vitro embryo production (IVP), however, the incidence and origin of chromosomal errors remains under-explored. To address this, we used single nucleotide polymorphism (SNP)-based PGT-A algorithms in 101 in vivo-derived (IVD) and 64 IVP porcine embryos. More errors were observed in IVP vs. IVD blastocysts (79.7% vs. 13.6% p < 0.001). In IVD embryos, fewer errors were found at blastocyst stage compared to cleavage (4-cell) stage (13.6% vs. 40%, p = 0.056). One androgenetic and two parthenogenetic embryos were also identified. Triploidy was the most common error in IVD embryos (15.8%), but only observed at cleavage, not blastocyst stage, followed by whole chromosome aneuploidy (9.9%). In IVP blastocysts, 32.8% were parthenogenetic, 25.0% (hypo-)triploid, 12.5% aneuploid, and 9.4% haploid. Parthenogenetic blastocysts arose from just three out of ten sows, suggesting a possible donor effect. The high incidence of chromosomal abnormalities in general, but in IVP embryos in particular, suggests an explanation for the low success of porcine IVP. The approaches described provide a means of monitoring technical improvements and suggest future application of PGT-A might improve embryo transfer success.

Comparing the advantages, disadvantages and diagnostic power of different non-invasive pre-implantation genetic testing: A literature review

To improve embryo transfer success and increase the chances of live birth in assisted reproductive methods, there is a growing demand for the use of pre-implantation genetic testing (PGT). However, the invasive approaches used in PGT have led to in vitrofertilization failure and abortions, increasing anxiety levels for parents. To address this, non-invasive PGT methods have been introduced, such as the detection of DNA in blastocoel fluid of blastocysts and spent culture media (SCM). These methods have proven to be minimally invasive and effective in detecting aneuploidy in the chromosomes of human embryos. This review aims to explore the different approaches to pre-implantation diagnosis, including invasive and non-invasive methods, with a particular focus on non-invasive PGT (niPGT). The search strategy involved gathering data from scientific databases such as PubMed, Google Scholar, and Science Direct using relevant keywords. The search was conducted until January 2023. In total, 22 studies have successfully reported the detection and amplification of cell-free DNA in the embryonic SCM. It is important to note that niPGT has some limitations, which include differences in indicators such as cell-free DNA amplification rate, concordance, level of maternal DNA contamination, sensitivity, and specificity between SCM samples and biopsied cells. Therefore, more extensive and detailed research is needed to fully understand niPGT's potential for clinical applications.

A hybrid artificial intelligence model leverages multi-centric clinical data to improve fetal heart rate pregnancy prediction across time-lapse systems

STUDY QUESTION

Can artificial intelligence (AI) algorithms developed to assist embryologists in evaluating embryo morphokinetics be enriched with multi-centric clinical data to better predict clinical pregnancy outcome?

SUMMARY ANSWER

Training algorithms on multi-centric clinical data significantly increased AUC compared to algorithms that only analyzed the time-lapse system (TLS) videos.

WHAT IS KNOWN ALREADY

Several AI-based algorithms have been developed to predict pregnancy, most of them based only on analysis of the time-lapse recording of embryo development. It remains unclear, however, whether considering numerous clinical features can improve the predictive performances of time-lapse based embryo evaluation.

STUDY DESIGN, SIZE, DURATION

A dataset of 9986 embryos (95.60% known clinical pregnancy outcome, 32.47% frozen transfers) from 5226 patients from 14 European fertility centers (in two countries) recorded with three different TLS was used to train and validate the algorithms. A total of 31 clinical factors were collected. A separate test set (447 videos) was used to compare performances between embryologists and the algorithm.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical pregnancy (defined as a pregnancy leading to a fetal heartbeat) outcome was first predicted using a 3D convolutional neural network that analyzed videos of the embryonic development up to 2 or 3 days of development (33% of the database) or up to 5 or 6 days of development (67% of the database). The output video score was then fed as input alongside clinical features to a gradient boosting algorithm that generated a second score corresponding to the hybrid model. AUC was computed across 7-fold of the validation dataset for both models. These predictions were compared to those of 13 senior embryologists made on the test dataset.

MAIN RESULTS AND THE ROLE OF CHANCE

The average AUC of the hybrid model across all 7-fold was significantly higher than that of the video model (0.727 versus 0.684, respectively, P = 0.015; Wilcoxon test). A SHapley Additive exPlanations (SHAP) analysis of the hybrid model showed that the six first most important features to predict pregnancy were morphokinetics of the embryo (video score), oocyte age, total gonadotrophin dose intake, number of embryos generated, number of oocytes retrieved, and endometrium thickness. The hybrid model was shown to be superior to embryologists with respect to different metrics, including the balanced accuracy (P ≤ 0.003; Wilcoxon test). The likelihood of pregnancy was linearly linked to the hybrid score, with increasing odds ratio (maximum P-value = 0.001), demonstrating the ranking capacity of the model. Training individual hybrid models did not improve predictive performance. A clinic hold-out experiment was conducted and resulted in AUCs ranging between 0.63 and 0.73. Performance of the hybrid model did not vary between TLS or between subgroups of embryos transferred at different days of embryonic development. The hybrid model did fare better for patients older than 35 years (P < 0.001; Mann-Whitney test), and for fresh transfers (P < 0.001; Mann-Whitney test).

LIMITATIONS, REASONS FOR CAUTION

Participant centers were located in two countries, thus limiting the generalization of our conclusion to wider subpopulations of patients. Not all clinical features were available for all embryos, thus limiting the performances of the hybrid model in some instances.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that considering clinical data improves pregnancy predictive performances and that there is no need to retrain algorithms at the clinic level unless they follow strikingly different practices. This study characterizes a versatile AI algorithm with similar performance on different time-lapse microscopes and on embryos transferred at different development stages. It can also help with patients of different ages and protocols used but with varying performances, presumably because the task of predicting fetal heartbeat becomes more or less hard depending on the clinical context. This AI model can be made widely available and can help embryologists in a wide range of clinical scenarios to standardize their practices.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for the study was provided by ImVitro with grant funding received in part from BPIFrance (Bourse French Tech Emergence (DOS0106572/00), Paris Innovation Amorçage (DOS0132841/00), and Aide au Développement DeepTech (DOS0152872/00)). A.B.-C. is a co-owner of, and holds stocks in, ImVitro SAS. A.B.-C. and F.D.M. hold a patent for 'Devices and processes for machine learning prediction of in vitro fertilization' (EP20305914.2). A.D., N.D., M.M.F., and F.D.M. are or have been employees of ImVitro and have been granted stock options. X.P.-V. has been paid as a consultant to ImVitro and has been granted stocks options of ImVitro. L.C.-D. and C.G.-S. have undertaken paid consultancy for ImVitro SAS. The remaining authors have no conflicts to declare.

TRIAL REGISTRATION NUMBER

N/A.

The far-reaching impact of abortion bans: reproductive care and beyond

On 24 June 2022, the US Supreme Court overturned Roe v. Wade, a 49-year-old precedent that provided federal constitutional protection for abortions up to the point of foetal viability, returning jurisdiction to the individual states. Restrictions that came into effect automatically in several states, and are anticipated in others, will severely limit access to abortions in approximately half of the US. Even though every state allows for exceptions to the abortion bans, in some instances these exceptions can be used to preserve the health of a pregnant patient, while in other instances, only to preserve their life. The vague and confusing nature of the abortion ban exceptions threatens to compromise the standard of care for patients with pregnancy complications that are distinct from abortions, such as nonviable pregnancies, miscarriages, and ectopic pregnancies. Additionally, we envision challenges for the treatment of women with certain autoimmune conditions, pregnant cancer patients, and patients contemplating preimplantation genetic diagnosis as part of assisted reproductive technologies. The abortion ban exceptions will impact and interfere with the medical care of pregnant and non-pregnant patient populations alike and are poised to create a medical and public health crisis unlike any other one from the recent past.

Obstetric, neonatal, and child health outcomes following embryo biopsy for preimplantation genetic testing

BACKGROUND

Preimplantation genetic testing (PGT) of embryos developed in vitro requires a biopsy for obtaining cellular samples for the analysis. Signs of cell injury have been described in association with this procedure. Thus, the consequences of the biopsy on obstetric and neonatal outcomes have been the subject of some quantitative analyses, although the reliability of data pooling may be limited by important issues in the various reports.

OBJECTIVE AND RATIONALE

The present review identifies evidence for whether pregnancies conceived after embryo biopsy are associated with a higher risk of adverse obstetric, neonatal, and long-term outcomes. Available evidence has been summarized considering manipulation at various stages of embryo development.

SEARCH METHODS

We used the scoping review methodology. Searches of article databases were performed with keywords pertaining to the embryo biopsy technique and obstetric, neonatal, and postnatal outcomes. Studies in which embryos were biopsied at different stages (i.e. both at the cleavage and blastocyst stages) were excluded. We included data on fresh and frozen embryo transfers. The final sample of 31 documents was subjected to qualitative thematic analysis.

OUTCOMES

Sound evidence is lacking to fully address the issues on the potential obstetric, neonatal or long-term consequences of embryo biopsy. For polar body biopsy, the literature is too scant to draw any conclusion. Some data, although limited and controversial, suggest a possible association of embryo biopsy at the cleavage stage with an increased risk of low birthweight and small for gestational age neonates compared to babies derived from non-biopsied embryos. An increase in preterm deliveries and birth defects in cases of trophectoderm biopsy was suggested. For both biopsy methods (at the cleavage and blastocyst stages), an increased risk for hypertensive disorders of pregnancy was found. However, these findings may be explained by confounders such as other embryo manipulation procedures or by intrinsic patient or population characteristics.

WIDER IMPLICATIONS

Since there is inadequate evidence to assess obstetric, neonatal, and long-term health outcomes following embryo biopsy, an invasive PGT strategy should be developed with a cautious approach. A non-invasive approach, based on the analysis of embryo cell-free DNA, needs to be pursued to overcome the potential limitations of embryo biopsy.

PGT pregnancies have a similar risk for post-partum complications as naturally conceived pregnancies

RESEARCH QUESTION

Do preimplantation genetic testing (PGT) pregnancies have higher post-partum complications compared with naturally conceived pregnancies?

DESIGN

Retrospective cohort study conducted in 2008-2020 at the Shaare Zedek Medical Center (SZMC), including all patients aged 18-45 years old who conceived following PGT with a singleton live birth >24 weeks. Data were collected from computerized hospital databases and patient files. There were two control groups: (i) pregnancies following IVF-ICSI (intracytoplasmic sperm injection); (ii) four neighbourhood controls for each case delivery (two women delivered before and two after) of women with naturally conceived pregnancies.

RESULTS

Overall, 120 PGT, 779 IVF-ICSI and 3507 naturally conceived deliveries were included. Demographic variables were similar apart from slightly higher age in the PGT (P = 0.003) and ICSI (P = 0.002) groups (31.07 ± 4.38 PGT, 31.66 ± 5.03 ICSI, 28.77 ± 5.72 naturally conceived). Composite post-partum placental-related complications (manual lysis of placenta, revision of uterine cavity, haemoglobin drop ≥3 g/dl, post-partum haemorrhage, need for blood transfusion) were more prevalent in both the PGT and IVF-ICSI groups as opposed to naturally conceived (20.0% versus 18.9% versus 10.3%, respectively, P < 0.001, P = 0.007). In a multivariate regression model PGT was not found to be independently associated with composite post-partum placental-related complications (adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 0.83-2.15), while IVF-ICSI pregnancies had increased risk (aOR 1.52, 95% CI 1.20-1.97) compared with natural conception. No difference was found between fresh and frozen cycles or between day 3 and day 5 embryo transfer.

CONCLUSIONS

PGT pregnancies have a comparable risk of post-partum placental-related complications to naturally conceived pregnancies, unlike IVF-ICSI pregnancies. It is possible that infertility itself is the main mediator for post-partum complications in IVF-ICSI pregnancies.

Assisted reproductive technology: Short- and long-term outcomes

Assisted reproductive technology (ART) includes fertility treatment in which either eggs or embryos are handled outside a female's body to promote successful pregnancies and healthy offspring. Current ART procedures encompass in vitro fertilization with or without intracytoplasmic sperm injection. The most common complication of ART is related to the consequences of multiple pregnancy, which can be prevented or minimized by reducing the number of embryos transferred to the uterus, commonly single embryo transfer. ART has been shown to be variably associated with adverse short- and long-term perinatal outcomes, including cerebral palsy, autism, neurodevelopmental imprinting disorders, and cancer. However, there is uncertainty as to whether reported problems are related to the ART procedure itself, to factors related to infertility, to other medical and environmental factors, or a combination thereof. From a pathophysiological perspective, whether ART alters epigenetic mechanisms of gene expression, leading to later developmental, medical, and behavioral disorders, is an area of active investigation. With the meticulously conducted short- and long-term outcome studies completed so far, overall, and after controlling for multiple gestations and preterm delivery, the results suggest that ART is a safe procedure, offering hope to many parent(s) wishing for a healthy child. This paper highlights ART methods and the risk factors and confounders in the interpretation of short- and long-term outcome data, providing the reader with a means to evaluate findings and conclusions of outcome studies. WHAT THIS PAPER ADDS: Assisted reproductive technology (ART) is a relatively safe procedure. Single embryo implantation optimizes outcome. Informed consent, including the risks and benefits of ART, should be required. Ongoing longitudinal studies are necessary to fully understand ART outcomes.

Preimplantation genetic testing for aneuploidy: challenges in clinical practice

Preimplantation genetic testing for aneuploidy (PGT-A) has been used widely during in vitro fertilization procedures in assisted reproductive centers throughout the world. Despite its wide use, concerns arise from the use of PGT-A technology in clinical decision-making. We address knowledge gaps in PGT-A, summarizing major challenges and current professional guidelines. First, PGT-A is a screening test and not a diagnostic test. Second, mosaicism is much higher in the blastocyst stage from PGT-A than had been recognized previously and a mosaic embryo may not accurately represent the genetic disease risk for future fetal disorders. Third, PGT-A was not validated clinically before use in patients; the best use of this technology for selected age-groups remains uncertain. Given these gaps, we believe that current professional policies relying on industry-self-regulation are insufficient. In the USA, the Food and Drug Administration may be the most appropriate agency to provide more definitive guidelines and regulations that are needed for better practice.

Infertility in systemic lupus erythematosus: what rheumatologists need to know in a new age of assisted reproductive technology

Fertility is often a concern for women with SLE. In addition to known indirect factors that influence the ability of a woman with SLE to become pregnant, such as cytotoxic agents, other medications, advanced age and psychosocial effects of the disease, direct disease-related factors are believed to influence fertility. These include diminished ovarian reserve, menstrual irregularities (a function of disease activity) and the presence of antiphospholipid antibodies. The question of whether SLE intrinsically affects fertility, however, remains unanswered. In this review, we address known factors affecting fertility, assess current data regarding a direct impact of SLE on fertility and evaluate potential disease-related risk factors. We focus primarily on studies measuring anti-Müllerian hormone and antral follicle count, the most widely measured markers of ovarian reserve. Our goal is to provide information to rheumatologists faced with counselling patients with SLE regarding their fertility, family planning and options for assisted reproductive technologies, which now include fertility preservation through oocyte cryopreservation.

Association of urinary bisphenol A concentrations with in vitro fertilisation outcomes: a systematic review and meta-analysis protocol

INTRODUCTION

Bisphenol A (BPA) is a common environmental endocrine disruptor. BPA has been reported to be associated with female infertility, which may not only affect natural pregnancy and natural fertility but also affect the outcomes of in vitro fertilisation (IVF). BPA exposure may help to partly explain the unsatisfactory IVF outcomes, but the relationship between the concentrations of BPA in urine and IVF outcomes remains controversial. Therefore, we will perform a meta-analysis to identify and review the relationship between urinary BPA concentrations and IVF outcomes.

METHODS AND ANALYSIS

A comprehensive literature search will be performed in PubMed, Web of Science and the Cochrane central register of controlled trials for relevant articles using MeSH terms and related entry terms (up to 20 April 2022). The language will be restricted to English. Articles will be screened for inclusion in or exclusion from the study independently by two reviewers after removing the duplicates. The titles and abstracts followed by full-text screening will also be conducted independently by two reviewers. In addition, the references of the included literature will also be traced to supplement our search results and to obtain all relevant literature. The Newcastle-Ottawa Scale will be used to assess the methodological quality of the included studies using a star rating system ranging from 0 to 9 stars. Heterogeneity in estimates from different articles will be quantified, and publication bias will be investigated using funnel plots. Finally, a sensitivity analysis will also be conducted to estimate whether our results could have been markedly affected by a single included study.

ETHICS AND DISSEMINATION

Ethical approval is not required for this protocol, as participants are not included. Findings will be disseminated through peer-reviewed publications and conference presentations.

Freeze all-first versus biopsy-first: A retrospective analysis of frozen blastocyst transfer cycles with preimplantation genetic testing for aneuploidy

Potential use of preimplantation genetic testing for aneuploidy (PGT-A) is increasing. Patients who have excess embryos cryopreserved at the blastocyst stage may desire PGT-A but there is little data available on options for these patients. We compared the efficacy and safety of the timing on the cryopreservation and trophectoderm(TE) biopsy for preimplantation genetic testing for aneuploidy (PGT-A) program associated with the better outcomes after frozen blastocyst transfer. Retrospective analysis of patients who underwent PGT-A cycles from January 2016 to December 2019 was carried out. 2684 blastocysts from cycles were subjected to TE biopsy for performing array comparative genomic hybridization test and Next-generation sequencing. All cycles were divided into two according to the timing of biopsy: biopsy-first (n = 211 cases/ 232 transfers) versus freeze all-first (n = 327 cases/ 415 transfers). In the biopsy-first group, embryos were cultured to expanded blastocyst and proceed to TE biopsy on day 5 or day 6 followed by cryopreservation. In the freeze all-first, blastocysts were vitrified and warmed before biopsy. Rates of clinical pregnancy (52.3% vs. 38.7%, P = 0.09) and ongoing pregnancy (44.3% vs. 34.5%, P = 0.07) in biopsy-first were significantly higher than those in freeze all-first. Biopsy-first showed comparable miscarriage rate with freeze all-first (15.2% (33/217) vs.11.1% (10/90), respectively). Rate ratio (RR) for clinical pregnancy was lower in freeze all-first group (adjusted RR = 0.78, 95% confidence interval: 0.65, 0.93). The RRs for miscarriage and live birth was also lower but it did not reach statistical significance. Our result supported performing TE biopsy of blastocyst for PGT-A before vitrification and warming. This finding would contribute to more evidence-based decision in PGT-A cycles.

microRNAs in the blastocoel fluid as accessible indicators of chromosomal normality

MicroRNAs (miRNAs) derived from the pre-implantation blastocoel fluid (BF) have attracted interest as accessible biomarkers indicative of embryonic health in ongoing IVF cycles. Therefore, we investigated expression levels of some aneuploidy-associated miRNAs and implantation-related mRNAs as predictive markers for embryo chromosomal normality. In this study, the BF of 25 blastocysts that had been checked for aneuploidy (aneuploid=17 and euploid=8) was aspirated and the expression of 10 miRNAs (miR-20a, miR-30c, miR-661, miR-372, miR-142, miR-191, miR-345, miR-339, miR-141, and miR-27b) and four genes (ERBB4, SELL, ITGB3, ITGAV) were evaluated using real time-PCR. Results showed that the levels of miR-661 and miR-20a were significantly higher in the BF of the aneuploid embryos compared to the euploid group (p = 0.0017 and 0.004, respectively). A comparison of the mRNA levels between the aneuploid and euploid groups also demonstrated a significant difference in ITGAV (p = 0.013) and SELL (p = 0.0317) levels. In the euploid group, a negative correlation was found between ITGB3 and miR-30c (r = -0.71, p = 0.08), and in the aneuploid group, a positive correlation was found between ERBB4 and miR-345 (r = 0.71, p = 0.02). It can be suggested that miR-20a, miR-661, and ITGAV levels of BF could be used as less-invasive biomarkers to evaluate embryonic health. Moreover, aneuploidy-related miRNA levels were associated with levels of genes involved in embryo implantation.

Development of an artificial intelligence model for predicting the likelihood of human embryo euploidy based on blastocyst images from multiple imaging systems during IVF

STUDY QUESTION

Can an artificial intelligence (AI) model predict human embryo ploidy status using static images captured by optical light microscopy?

SUMMARY ANSWER

Results demonstrated predictive accuracy for embryo euploidy and showed a significant correlation between AI score and euploidy rate, based on assessment of images of blastocysts at Day 5 after IVF.

WHAT IS KNOWN ALREADY

Euploid embryos displaying the normal human chromosomal complement of 46 chromosomes are preferentially selected for transfer over aneuploid embryos (abnormal complement), as they are associated with improved clinical outcomes. Currently, evaluation of embryo genetic status is most commonly performed by preimplantation genetic testing for aneuploidy (PGT-A), which involves embryo biopsy and genetic testing. The potential for embryo damage during biopsy, and the non-uniform nature of aneuploid cells in mosaic embryos, has prompted investigation of additional, non-invasive, whole embryo methods for evaluation of embryo genetic status.

STUDY DESIGN, SIZE, DURATION

A total of 15 192 blastocyst-stage embryo images with associated clinical outcomes were provided by 10 different IVF clinics in the USA, India, Spain and Malaysia. The majority of data were retrospective, with two additional prospectively collected blind datasets provided by IVF clinics using the genetics AI model in clinical practice. Of these images, a total of 5050 images of embryos on Day 5 of in vitro culture were used for the development of the AI model. These Day 5 images were provided for 2438 consecutively treated women who had undergone IVF procedures in the USA between 2011 and 2020. The remaining images were used for evaluation of performance in different settings, or otherwise excluded for not matching the inclusion criteria.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The genetics AI model was trained using static 2-dimensional optical light microscope images of Day 5 blastocysts with linked genetic metadata obtained from PGT-A. The endpoint was ploidy status (euploid or aneuploid) based on PGT-A results. Predictive accuracy was determined by evaluating sensitivity (correct prediction of euploid), specificity (correct prediction of aneuploid) and overall accuracy. The Matthew correlation coefficient and receiver-operating characteristic curves and precision-recall curves (including AUC values), were also determined. Performance was also evaluated using correlation analyses and simulated cohort studies to evaluate ranking ability for euploid enrichment.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall accuracy for the prediction of euploidy on a blind test dataset was 65.3%, with a sensitivity of 74.6%. When the blind test dataset was cleansed of poor quality and mislabeled images, overall accuracy increased to 77.4%. This performance may be relevant to clinical situations where confounding factors, such as variability in PGT-A testing, have been accounted for. There was a significant positive correlation between AI score and the proportion of euploid embryos, with very high scoring embryos (9.0-10.0) twice as likely to be euploid than the lowest-scoring embryos (0.0-2.4). When using the genetics AI model to rank embryos in a cohort, the probability of the top-ranked embryo being euploid was 82.4%, which was 26.4% more effective than using random ranking, and ∼13-19% more effective than using the Gardner score. The probability increased to 97.0% when considering the likelihood of one of the top two ranked embryos being euploid, and the probability of both top two ranked embryos being euploid was 66.4%. Additional analyses showed that the AI model generalized well to different patient demographics and could also be used for the evaluation of Day 6 embryos and for images taken using multiple time-lapse systems. Results suggested that the AI model could potentially be used to differentiate mosaic embryos based on the level of mosaicism.

LIMITATIONS, REASONS FOR CAUTION

While the current investigation was performed using both retrospectively and prospectively collected data, it will be important to continue to evaluate real-world use of the genetics AI model. The endpoint described was euploidy based on the clinical outcome of PGT-A results only, so predictive accuracy for genetic status in utero or at birth was not evaluated. Rebiopsy studies of embryos using a range of PGT-A methods indicated a degree of variability in PGT-A results, which must be considered when interpreting the performance of the AI model.

WIDER IMPLICATIONS OF THE FINDINGS

These findings collectively support the use of this genetics AI model for the evaluation of embryo ploidy status in a clinical setting. Results can be used to aid in prioritizing and enriching for embryos that are likely to be euploid for multiple clinical purposes, including selection for transfer in the absence of alternative genetic testing methods, selection for cryopreservation for future use or selection for further confirmatory PGT-A testing, as required.

STUDY FUNDING/COMPETING INTEREST(S)

Life Whisperer Diagnostics is a wholly owned subsidiary of the parent company, Presagen Holdings Pty Ltd. Funding for the study was provided by Presagen with grant funding received from the South Australian Government: Research, Commercialisation, and Startup Fund (RCSF). 'In kind' support and embryology expertise to guide algorithm development were provided by Ovation Fertility. 'In kind' support in terms of computational resources provided through the Amazon Web Services (AWS) Activate Program. J.M.M.H., D.P. and M.P. are co-owners of Life Whisperer and Presagen. S.M.D., M.A.D. and T.V.N. are employees or former employees of Life Whisperer. S.M.D, J.M.M.H, M.A.D, T.V.N., D.P. and M.P. are listed as inventors of patents relating to this work, and also have stock options in the parent company Presagen. M.V. sits on the advisory board for the global distributor of the technology described in this study and also received support for attending meetings.

TRIAL REGISTRATION NUMBER

N/A.

ISPD 2021 Debate - All IVF cycles should involve pre-implantation genetic testing to improve fetal health and pregnancy outcomes

For three decades, couples at increased risk for a genetic disorder have been offered preimplantation genetic testing (PGT). Simultaneously, PGT for aneuploidy (PGT-A) to improve in vitro fertilization (IVF) outcomes was introduced, but evidence of value-added remains inconsistent. Recently, lower genetic testing costs and shorter turnaround time have reinvigorated PGT-A. Additionally, a shift from blastomere (day 3) to blastocyst (day 5) transfer and embryo freezing advances support PGT without the time constraints of immediate transfer. PGT-A transformed from a time-constrained analysis of 1-2 cells to an "add on" study for all IVF. But should it be offered to all IVF patients? And if not, under what conditions? Pre-debate polling found 64% opposed to PGT for all IVF cycles with concerns voiced about cost, informed consent, and a "slippery slope". Leaving aside the inconsistent evidence of IVF improvement whether measured as miscarriage or livebirths with PGT-A, the debaters grappled with patient and provider desires versus the ethical concerns for the unborn child. However, the audience was not swayed; two thirds remained opposed to PGT for all IVF cycles. This article is protected by copyright. All rights reserved.

Chromosome Segregation in the Oocyte: What Goes Wrong during Aging

Human female fertility and reproductive lifespan decrease significantly with age, resulting in an extended post-reproductive period. The central dogma in human female reproduction contains two important aspects. One is the pool of oocytes in the human ovary (the ovarian reserve; approximately 10⁶ at birth), which diminishes throughout life until menopause around the age of 50 (approximately 10³ oocytes) in women. The second is the quality of oocytes, including the correctness of meiotic divisions, among other factors. Notably, the increased rate of sub- and infertility, aneuploidy, miscarriages, and birth defects are associated with advanced maternal age, especially in women above 35 years of age. This postponement is also relevant for human evolution; decades ago, the female aging-related fertility drop was not as important as it is today because women were having their children at a younger age. Spindle assembly is crucial for chromosome segregation during each cell division and oocyte maturation, making it an important event for euploidy. Consequently, aberrations in this segregation process, especially during the first meiotic division in human eggs, can lead to implantation failure or spontaneous abortion. Today, human reproductive medicine is also facing a high prevalence of aneuploidy, even in young females. However, the shift in the reproductive phase of humans and the strong increase in errors make the problem much more dramatic at later stages of the female reproductive phase. Aneuploidy in human eggs could be the result of the non-disjunction of entire chromosomes or sister chromatids during oocyte meiosis, but partial or segmental aneuploidies are also relevant. In this review, we intend to describe the relevance of the spindle apparatus during oocyte maturation for proper chromosome segregation in the context of maternal aging and the female reproductive lifespan.

Identification of Pathogenic Variants in RPGRIP1L with Meckel Syndrome and Preimplantation Genetic Testing in a Chinese Family

Meckel syndrome (MKS, OMIM:249000) is a severe multiorgan dysplastic lethal ciliopathy with extreme genetic heterogeneity. Defects in RPGRIP1L are the cause of MKS type 5 (MKS5, OMIM:611561). However, only six different variants have been reported in eight MKS5 cases with biallelic variants. Here, we describe the case of a Chinese family with recurrent fetal malformations. The proband was a 14-week gestation fetus with occipital encephalocele, polycystic kidneys, polydactyly, and single ventricular heart. Trio whole-exome sequencing was performed, and two novel compound heterozygous variants of RPGRIP1L (c.427C > T, p.Gln143Ter and c.1351-11A > G) were identified. cDNA studies of the splicing variant demonstrated a reading-frame shift with a subsequent premature stop codon (p.Glu451Serfs*6). After the proband was diagnosed with MKS5, the couple chose preimplantation genetic testing for monogenic disorders (PGT-M) and prenatal genetic diagnosis (PND) to prevent the transmission of pathogenic variants, which led to a successful pregnancy recently. In summary, we have identified two novel variants of RPGRIP1L in a Chinese family, which expand the variant spectrum of MKS5. Furthermore, we have described the successful application of PGT-M and PND in this family. These techniques could assist couples with a genetic predisposition in avoiding the transmission of genetic diseases to their offspring.

Factors affecting clinical manifestation of chromosomal imbalance in carriers of segmental autosomal mosaicism: differential impact of gender

Mosaicism for unbalanced chromosomal rearrangements segmental mosaicism (SM) is rare, both in patients referred for cytogenetic testing and in prenatal diagnoses. In contrast, in preimplantation embryos SM is a frequent finding and, therefore, is even more challenging. However, there is no consistency among results of published studies on the clinical outcomes of embryos with SM, primarily due to the small number of reported cases. Moreover, there is the problem of predicting the potential for the optimal development of a mosaic embryo to a healthy individual. Therefore, we suggested comparing factors predisposing to favorable and poor prognoses, identified in postnatal and prenatal cohorts of SM carriers, with those obtained from studies on preimplantation embryos. We analyzed 580 published cases of SM including (i) postnatally diagnosed affected carriers, (ii) clinically asymptomatic carriers, (iii) prenatally diagnosed carriers, and (iv) miscarriages. We observed a concordance with preimplantation diagnoses regarding the clinical significance of the extent of mosaicism as well as a predominance of deletions over other types of rearrangements. However, there is no concordance regarding excessive involvement of chromosomes 1, 5, and 9 in unbalanced rearrangements and a preferential involvement of larger chromosomes compared to short ones. Paternal age was not found to be associated with SM in postnatally disease-defined individuals. We have identified maternal age and preferential involvement of chromosome 18 in rearrangements associated with clinical manifestations. Male predominance was found among normal pregnancy outcomes and among disease-defined carriers of rearrangements resulting in a gain of genomic material. Female predominance was found among abnormal pregnancy outcomes, among disease-defined carriers of loss and gain/loss rearrangements, and among transmitting carriers of gonadal SM, both affected and asymptomatic. According to data obtained from “post-embryo” studies, clinical manifestations of chromosomal imbalance are associated with a high proportion of abnormal cells, female gender, the type of rearrangement and involved chromosome(s), and maternal age. We believe these data are instructive in the challenging medical genetic counseling of parents faced with no option other than transfer of an embryo with segmental mosaicism.

Live Birth with or without Preimplantation Genetic Testing for Aneuploidy

BACKGROUND

Embryo selection with preimplantation genetic testing for aneuploidy (PGT-A) may improve pregnancy outcomes after initial embryo transfer. However, it remains uncertain whether PGT-A improves the cumulative live-birth rate as compared with conventional in vitro fertilization (IVF).

METHODS

In this multicenter, randomized, controlled trial, we randomly assigned subfertile women with three or more good-quality blastocysts to undergo either PGT-A or conventional IVF; all the women were between 20 and 37 years of age. Three blastocysts were screened by next-generation sequencing in the PGT-A group or were chosen by morphologic criteria in the conventional-IVF group and then were successively transferred one by one. The primary outcome was the cumulative live-birth rate after up to three embryo-transfer procedures within 1 year after randomization. We hypothesized that the use of PGT-A would result in a cumulative live-birth rate that was no more than 7 percentage points higher than the rate after conventional IVF, which would constitute the noninferiority margin for conventional IVF as compared with PGT-A.

RESULTS

A total of 1212 patients underwent randomization, and 606 were assigned to each trial group. Live births occurred in 468 women (77.2%) in the PGT-A group and in 496 (81.8%) in the conventional-IVF group (absolute difference, -4.6 percentage points; 95% confidence interval [CI], -9.2 to -0.0; P<0.001). The cumulative frequency of clinical pregnancy loss was 8.7% and 12.6%, respectively (absolute difference, -3.9 percentage points; 95% CI, -7.5 to -0.2). The incidences of obstetrical or neonatal complications and other adverse events were similar in the two groups.

CONCLUSIONS

Among women with three or more good-quality blastocysts, conventional IVF resulted in a cumulative live-birth rate that was noninferior to the rate with PGT-A. (Funded by the National Natural Science Foundation of China and others; ClinicalTrials.gov number, NCT03118141.).

Infertility and subsequent recurrent miscarriage: Current state of the literature and future considerations for practice and research

Background: Recurrent miscarriage (RM) and infertility are independently associated with adverse pregnancy outcomes, in addition to psychological sequelae. Experiencing pregnancy loss alongside infertility is particularly difficult. International guidance regarding RM is conflicting, and applicability to women with infertility is undetermined. The aim of this study was to: (i) establish if women/couples with a history of infertility are recognised in the literature on the investigation and management of RM, and (ii) determine if the specific needs of women/couples experiencing RM and infertility are ascertained and incorporated into clinical management strategies. Methods: We examined the wide-ranging literature to ascertain what gaps existed. Studies were retrieved through searches of PubMed and Google Scholar up to 21 January 2021 using appropriate controlled vocabulary and combinations of key words. No language or study design restrictions were applied. Results: While women/couples experiencing RM after infertility appear in studies evaluating investigations and proposed treatments, high-quality studies are lacking. Furthermore, they are largely excluded from international clinical guidance and qualitative research. Conclusions: The experiences of women/couples with RM and infertility and their specific care needs within maternity and fertility services are underexplored. It is unclear from current RM guidelines how best to manage and support this complex cohort. Women/couples with infertility and RM are underserved in the literature and in clinical guidance. Further robust studies are warranted to examine pregnancy outcomes, investigations and treatments currently used. Qualitative research is also required to identify their medical and psychological needs to better support this vulnerable group.