Prediction of embryo euploidy and pregnancy outcome by blastocyst morphology and development speed for women receiving single embryo transfer

BACKGROUND

Selection of high-quality blastocysts is the most important factor determining the success of assisted reproductive technology. The objective of this study is to assess the values of blastocyst morphological quality and development speed for predicting euploidy and clinical pregnancy outcome.

METHODS

A total of 155 preimplantation genetic testing cycles including 959 blastocysts and 154 euploid blastocyst transfer cycles conducted between January 2018 and December 2019 were retrospectively analysed. The associations of blastocyst morphological quality and development speed (D) with chromosomal status, clinical pregnancy rate, early miscarriage rate, and ongoing pregnancy rate were evaluated by univariate and multivariate regression.

RESULTS

The euploidy rate of development speed D5 blastocysts was significantly greater than that of D6 blastocysts (61.4% vs. 38.1%, P < 0.001), and the euploid rate of morphologically high-grade blastocysts was significantly greater than that of non-high-grade blastocysts. Development speed D5 (OR = 1.6, 95% CI 1.2-2.2, P = 0.02) and high-grade morphology (OR = 2.1, 95% CI 1.5-2.9, P = 0.01) were independent predictors of euploidy. The ongoing pregnancy rate of D5 blastocysts was significantly higher than that of D6 blastocysts (62.3% vs. 43.8%, P = 0.04). Transfer of euploid blastocysts with high-grade morphology resulted in a greater ongoing pregnancy rate than transfer of non-high-grade euploid blastocysts (60.7% vs. 43.2%, P = 0.049). Alternatively, D6 development speed was an independent risk factor for early pregnancy loss after euploid blastocyst transfer. Multivariate regression analysis adjusting for confounding factors identified maternal age, blastocyst development speed, and blastocyst morphological grade as independent predictors of euploidy but not of clinical pregnancy.

CONCLUSION

The recommended sequence of embryo transfer based on the present study is D5 high-grade > D6 high-grade > D5 non-high-grade > D6 non-high-grade.

Preimplantation genetic testing in the current era, a review

BACKGROUND

Preimplantation genetic testing (PGT), also referred to as preimplantation genetic diagnosis (PGD), is an advanced reproductive technology used during in vitro fertilization (IVF) cycles to identify genetic abnormalities in embryos prior to their implantation. PGT is used to screen embryos for chromosomal abnormalities, monogenic disorders, and structural rearrangements.

DEVELOPMENT OF PGT

Over the past few decades, PGT has undergone tremendous development, resulting in three primary forms: PGT-A, PGT-M, and PGT-SR. PGT-A is utilized for screening embryos for aneuploidies, PGT-M is used to detect disorders caused by a single gene, and PGT-SR is used to detect chromosomal abnormalities caused by structural rearrangements in the genome.

PURPOSE OF REVIEW

In this review, we thoroughly summarized and reviewed PGT and discussed its pros and cons down to the minutest aspects. Additionally, recent studies that highlight the advancements of PGT in the current era, including their future perspectives, were reviewed.

CONCLUSIONS

This comprehensive review aims to provide new insights into the understanding of techniques used in PGT, thereby contributing to the field of reproductive genetics.

The utility of human two plus one small pronucleated zygotes (2.1PN) based on clinical outcomes and the focused ploidy analysis

PURPOSE

Are human embryos arising from two plus one small pronucleated zygotes, called 2.1 pronuclei (PN), clinically useful?

METHODS

In a retrospective embryo cohort study and prospective experimental study, a total of 287 cycles in which at least one 2.1PN was identified in the fertilization check were included. Embryonic development and clinical outcome were compared for the 1395 2PN zygotes and 304 2.1PN zygotes that were siblings. All embryos were individually cultured in time-lapse systems. Twenty-five 2.1PN-derived blastocysts, donated for research, were used in focused single-nucleotide variant ploidy analysis to identify the distribution pattern of heterozygosity.

RESULTS

The average diameter of PN was 24.9 ± 2.4 µm for large PN and 10.2 ± 2.4 µm for small PN; 79.9% of small PN was derived from female pronuclei. Blastocyst formation rate and good-quality blastocyst rate were significantly lower with 2.1PN embryos than with 2PN embryos (40.0% vs. 57.7%, 21.4% vs. 33.5%, respectively). A total of 13 embryos derived from 2.1PN were transferred, and three healthy babies were born. In ploidy constitutions of trophectoderm (TE), 2.1PN-derived blastocyst TE was shown to be mostly diploid (95.8%, 23/24), and only one blastocyst showed triploid.

CONCLUSIONS

It was suggested that 2.1PN embryos have lower embryonic developmental potential than 2PN embryos, but most of the 2.1PN were diploid, indicating that they are likely to be clinically usable. It is recommended to perform embryo transfer following a combination of PGT-A and ploidy analysis.

Increasing Endometrial Thickness Beyond 8 mm Does Not Alter Clinical Pregnancy Rate After Single Euploid Embryo Transfer

The aim of this study was to investigate if variation in endometrial thickness affects clinical pregnancy and live birth rates among patients undergoing single euploid embryo transfer (SET). A retrospective review of IVF cycles performed at a single private fertility institution between 2015 and 2020 was performed. Patients with normal uterine anatomy undergoing their first SET of a euploid embryo undergoing their first cycle at the center were included, for a total of 796 cycles. Endometrial thickness was measured by transvaginal ultrasound following 10-14 days of estradiol exposure. Specific infertility diagnoses did not significantly impact endometrial lining thickness with means across diagnoses ranging from 9.3 to 11.0 mm. Endometrial thickness was grouped into five categories: < 8 mm, 8-10 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm. Using 8-10 mm as the reference group, the odds ratio of live birth was 0.5, 1.22, 1.05, and 1.05 for < 8 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm groups, respectively. Risk of first trimester miscarriage was equivalent across groups. There was a trend toward an increased rate of biochemical pregnancies in patients with a < 8 mm and ≥ 15 mm endometrium; however, this was not statistically significant. The clinical pregnancy and live birth rate were lowest in patients with < 8-mm endometrial thickness. For single euploid embryo transfers, an endometrial lining greater than or equal to 8 mm confers optimal live birth rates following a medicated FET cycle. These data confirm the findings of prior studies in fresh embryo transfers without the confounders of supraphysiologic ovarian hormone concentrations and genetically untested embryos.

Patient interest in and clinician reservations on polygenic embryo screening: a qualitative study of stakeholder perspectives

PURPOSE

We explored and compared perspectives of reproductive endocrinology and infertility specialists (REIs) and in vitro fertilization (IVF) patients regarding polygenic embryo screening (PES), a new type of preimplantation screening that estimates the genetic chances of developing polygenic conditions and traits in the future.

METHODS

Qualitative thematic analysis of semi-structured interviews with US-based REIs and IVF patients.

RESULTS

Clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more frequently than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer PES to patients or were willing to do so only under certain circumstances, while many patients expressed interest in PES. Both stakeholder groups envisioned multiple potential benefits or uses of PES and raised multiple potential, interrelated concerns about PES.

CONCLUSION

A gap exists between clinician and patient attitudes toward PES; clinicians generally maintained reservations about such screening and patients indicated interest in it. Clinicians and patients sometimes imagined using PES to prepare for the birth of a predisposed or "affected" individual-a rationale that is often associated with prenatal testing. Many clinicians and patients held different attitudes depending on what is specifically screened, despite the sometimes blurry distinction between conditions and traits. Considerations raised by clinicians and patients may help guide professional societies in developing guidelines to navigate the uncertain terrain of PES.

The impact of first-trimester subchorionic hematomas on pregnancy outcomes after euploid embryo transfer: a retrospective cohort study

BACKGROUND

The aim of the retrospective cohort study was to investigate the prognostic effect of subchorionic hematomas (SCH) in the first trimester on pregnancy outcomes after euploid embryo transfer.

METHODS

We retrospectively analyzed women achieving singleton pregnancy by PGT-A or PGT-SR from January 2017 to January 2022. Patients were enrolled in the study if they had a viable intrauterine pregnancy at ultrasound between 6 0/7 and 8 0/7 weeks of gestation. Pregnancy outcomes as well as the incidence of maternal complications were compared between patients with and without SCH. Logistic regression was used for adjusting for potential confounding factors.

RESULTS

A total of 1539 women were included, of which 298 with SCH and 1241 with non-SCH. The early miscarriage rate in SCH group was significantly higher than that in the non-SCH group (10.1% vs. 5.6%, adjusted odds ratio [aOR] 1.99, 95% confidence interval [CI] 1.25-3.16, P = 0.003). The live birth rate in SCH group was significantly lower than that in the non-SCH group. (85.6% vs. 91.2%, aOR 0.57, 95% CI 0.39-0.84, P = 0.005). In addition, SCH group had an increased risk of hypertensive disorder of pregnancy (HDP) (8.9% vs. 5.2%, P = 0.022), especially in hematoma with bleeding (19.3% vs. 6.0%, P = 0.002). The incidence of gestational diabetes mellitus (GDM), major congenital abnormalities rate, normal birth weight rate and low birth weight rate were similar between the two groups.

CONCLUSIONS

The presence of SCH in the first trimester was associated with worse pregnancy outcomes after euploid embryo transfer, including an increased risk of early miscarriage and hypertensive disorder of pregnancy, along with a reduced live birth rate.

A clinical predictive model for live birth in women of advanced age undergoing PGT cycles

PURPOSE

The trend of delaying childbirth has resulted in a growing number of advanced-aged women who are opting for preimplantation genetic testing (PGT) to screen for monogenic diseases or structural chromosomal rearrangements (PGT-M and PGT-SR). This increase in demand necessitates the development of a clinical predictive model for live birth outcomes in these women. Therefore, the objective of this study is to construct a comprehensive predictive model that assesses the likelihood of achieving a successful live birth in advanced-aged women undergoing PGT-M and PGT-SR treatments.

METHODS

A retrospective cohort study of 37-45-year-old women undergoing preimplantation genetic testing for monogenic disease or structural chromosomal rearrangement cycles from 2010 to 2021 was conducted at a university hospital reproductive centre. The purpose was to develop a clinical predictive model for live birth in these women. The main outcome studied was the cumulative live birth rate in the first or subsequent cycles. Developing a decision tree enabled a comprehensive study of clinical parameters and expected outcomes.

RESULTS

The analysis included 158 women undergoing 753 preimplantation genetic testing cycles. The cumulative live birth rate was 37.342% (59/158). Decision tree analysis revealed that women aged ≤ 40.1 or women > 40.1 with one or more top-quality transferable embryos in their first cycle had the best chance for a live baby (56% and 41%, respectively). Those older than 40.1 without top-quality embryos and seven or fewer dominant follicles had no live births. A Kaplan-Meier curve showed that for autosomal dominant diseases, there was a negligible increase in live birth rate after three cycles, compared to six cycles in autosomal recessive inheritance.

CONCLUSION

In older women, the chance of delivering after repeated cycles is higher in those with at least one top-quality unaffected embryo in their first preimplantation genetic testing cycle. Additional preimplantation genetic testing cycles after three in carriers of an autosomal dominant disorder and six in those with an autosomal recessive disorder should be considered prudently.

Does embryo biopsy, independent of vitrification, impact perinatal outcomes? An analysis of perinatal outcomes following preimplantation genetic testing biopsy in fresh and frozen embryo transfer cycles

Objective

To compare neonatal outcomes in pregnancies resulting from embryos that have undergone preimplantation genetic testing (PGT) biopsy compared with no biopsy in both fresh and frozen embryo transfers (ETs) and determine whether findings are mediated by multiple births.

Design

Retrospective cohort study.

Setting

Society of Assisted Reproductive Technologies-Clinical Outcomes Reporting System data, 2014-2015.

Patients

Autologous in vitro fertilization treatment cycles using fresh or frozen blastocyst ET, with or without PGT biopsy.

Interventions

Not applicable.

Main Outcome Measures

Large for gestational age (LGA), small for gestational age, and preterm delivery. Secondary outcomes included high birthweight, low birthweight, and clinical pregnancy measures. Outcomes were evaluated using log-binomial regression models with repeated measures. Models were used to estimate the controlled direct effects of biopsy on birth outcomes that were not mediated by multiple gestations.

Results

In fresh ET, biopsy was associated with an increase in LGA (relative risk [RR] 1.45, confidence interval [CI] 1.04-2.02) that persisted in the model mediated for multiple gestation (RR 1.36, 95% CI 1.01-1.83) but was not present in an analysis restricted to elective single ET (RR 0.99, 95% CI 0.91-1.09). In frozen ET, there were no differences in any of the primary outcomes after accounting for multiple gestations.

Conclusions

In a large multicenter database, there were no differences in neonatal outcomes after PGT biopsy in frozen ET cycles, and an increase in LGA was noted in fresh transfers that persisted even after accounting for multiple gestations but was not present in analysis restricted to elective single ET.

To transfer or not to transfer: the dilemma of mosaic embryos - a narrative review

A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both). The origin of mosaicism seems to be intrinsic as a post-zygotic mitotic error, but some external factors can play a role. As experience has increased with the transfer of mosaic embryos, clinical practice has gradually become more flexible in recent years. Nevertheless, clinical results show lower implantation, pregnancy and clinical pregnancy rates and higher miscarriage rates with mosaic embryo transfer when compared with the transfer of euploid embryos. Prenatal diagnosis is highly recommended after the transfer of mosaic embryos. This narrative review is intended to serve as reference material for practitioners in reproductive medicine who must manage a mosaic embryo result after preimplantation genetic testing for aneuploidies.

The first clinical validation of whole-genome screening on standard trophectoderm biopsies of preimplantation embryos

Objective

To validate the performance of our laboratory-developed whole-genome screening assay within clinical preimplantation genetic testing environments.

Design

Perform a laboratory-developed whole-genome assay on both cell lines and trophectoderm biopsies, subsequently employing the next-generation sequencing procedure to reach a sequencing depth of 30X. Adhere to the Genome Analysis Toolkit best practices for accuracy, sensitivity, specificity, and precision calculations by comparing samples with references. Our assay was then applied to cell lines and biopsies harboring known pathogenic variants, aiming to ascertain these changes solely from the next-generation sequencing data, independent of parental genome information.

Settings

Clinical laboratory.

Patients

Coriell cell lines and research embryos with known chromosomal or genetic variants. Research trophectoderm biopsies from a couple that are heterozygous carriers for distinct variants in the same autosomal recessive gene (HOGA1).

Intervention

Not applicable.

Main Outcome Measures

Accuracy, sensitivity, specificity, and precision were assessed by comparing the samples to their references. For samples with known variants, we calculated our sensitivity to detecting established variants. For the research embryos, noncarrier, carrier, and compound heterozygous states of inherited HOGA1 variants were distinguished independently of parental samples.

Results

Amplification of DNA from cell lines and embryos yielded success rates exceeding 99.9% and 98.2%, respectively, although maintaining an accuracy of >99.9% for aneuploidy assessment. The accuracy (99.99%), specificity (99.99%), sensitivity (98.0%), and precision (98.1%) of amplified genome in the bottle (reference NA12878) and embryo biopsies were comparable to results on genomic DNA, including mitochondrial heteroplasmy. Using our assay, we achieved >99.99% sensitivity when examining samples with known chromosomal and genetic variants. This encompassed pathogenic CFTR, BRCA1, and other variants, along with uniparental isodisomies and microdeletions such as DiGeorge syndrome. Our research study identified noncarrier, carrier, and compound heterozygous states within trophectoderm biopsies while simultaneously screening for 1,300 other severe monogenic diseases.

Conclusion

To our knowledge, this is the first clinical validation of whole-genome embryo screening. In this study, we demonstrated high accuracy for aneuploidy calls (>99.9%) and genetic variants (99.99%), even in the absence of parental genomes. This assay demonstrates advancements in genomic screening and an extended scope for testing capabilities in the realm of preimplantation genetic testing.

Correlation of self-reported racial background to euploidy status and live birth rates in assisted reproductive technology cycles

PURPOSE

To determine whether the embryonic euploidy rate and live birth outcomes following single, euploid embryo transfer (SEET) differ among women of self-reported racial and ethnic backgrounds.

METHODS

This retrospective cohort study included all infertile patients of different self-reported racial backgrounds who underwent In vitro fertilization (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) and an autologous single euploid embryo transfer (SEET) from December 2015 to December 2019 at a single private and academic assisted reproduction technology center. Primary outcome measures included ploidy rates among different racial groups. Secondary outcomes included clinical pregnancy, clinical pregnancy loss, and live birth rates.

RESULTS

Five thousand five hundred sixty-two patients who underwent an IVF cycle with ICSI-PGT-A were included. A total of 24,491 blastocysts were analyzed. White participants had on average more euploid embryos and higher euploidy rates when compared to their counterparts (p ≤ 0.0001). However, after controlling for confounding factors, there was no association between race and the odds of having  a higher euploidy rate (aOR 1.31; 95% CI 0.63-2.17, p = 0.42). A total of 4949 patients underwent SEET. Pregnancy outcomes did not differ among patients of varying self-reported races.

CONCLUSIONS

Euploidy rates and pregnancy outcomes were comparable among patients of different racial backgrounds who underwent a SEET.

Impact of aneuploidy on reproductive success in young infertile women: prospective analysis

RESEARCH QUESTION

What is the clinical outcome of the first attempt at conception between two embryo selection methods, blastocyst morphology and preimplantation genetic testing for aneuploidies (PGT-A), chosen at the initial physician IVF consultation?

DESIGN

In this prospective analysis, a clinical decision regarding embryo selection, blastocyst morphology (group A) or PGT-A (group B) was made during initial physician IVF consultation. Female infertility patients were matched based on maternal age (mean 32.6 ± 3.6 years; range 25-43 years) and a similar time frame of oocyte retrieval. The primary outcome was live birth rate from the initial consultation to the first conception attempt for all female patients and for a subset analysis of patients aged <35 years.

RESULTS

The inclusion of PGT-A (group B) for embryo selection during the initial physician IVF consultation resulted in 23 additional women out of the total 100 achieving a healthy live birth following the first conception attempt in this maternally age-matched infertile population (group B = 72.0% versus group A = 49.0%; P = 0.0014). This same benefit was observed for age-matched, younger infertility patients (<35 years), with live birth rates from the initial consultation being significantly higher when the upfront clinical decision included PGT-A for embryo selection (group B = 76.7% versus group A = 53.4%; P = 0.0052). Interestingly, 17 women from group B would have received an aneuploid embryo transfer if selection had been determined by blastocyst morphology alone, as their best-grade embryo was aneuploid.

CONCLUSIONS

This prospective analysis from the initial physician IVF consultation revealed that euploid embryo selection significantly improved live birth potential with the first conception attempt, even for younger women with infertility.

Antibiotic cured chronic endometritis remains a risk factor for early pregnancy loss in the subsequent frozen euploid embryo transfer

RESEARCH QUESTION

Do patients with antibiotic-cured chronic endometritis (CCE) have a comparable pregnancy outcome to those with non-chronic endometritis (NCE) in the subsequent frozen embryo transfer (FET) cycle?

DESIGN

A retrospective cohort analysis included 833 patients in their first FET cycles with single euploid embryo transfer. Chronic endometritis (≥5 CD138+ plasma cells per high-power field [CD138+/HPF]) was treated with standard antibiotic therapy. Patients were classified into two groups: the NCE group (n = 611, <5 CD138+/HPF) and the CCE group (n = 222, ≥5 CD138+/HPF and cured after antibiotic treatment). Pregnancy outcomes were compared. NCE group was divided into subgroup 1 (CD138+/HPF = 0) and subgroup 2 (CD138+/HPF = 1-4) for further analysis.

RESULTS

The rate of early pregnancy loss (EPL), incorporating all losses before 10 weeks' gestation, was significantly higher in the CCE group than the NCE group (21.2% versus 14.2%, P = 0.016), and the difference was statistically significant (adjusted odds ratio [AOR] 1.68, 95% confidence interval [CI] 1.11-2.55). No significant differences were observed between the two groups with regard to other pregnancy outcomes. In the subgroup analysis, the EPL rate and biochemical pregnancy rate were significantly higher in subgroup 2 than subgroup 1 (17.2% versus 9.4%, AOR 2.21, 95% CI 1.30-3.74; 12.2% versus 6.9%, AOR 2.01, 95% CI 1.09-3.68).

CONCLUSIONS

Chronic endometritis cured by standard antibiotic therapy remains a risk factor for EPL in FET cycles, although no differences were found in live birth rates between patients with CCE or with NCE.

Reproductive outcomes of single frozen-thawed embryo transfer in patients with endometriosis after preimplantation genetic testing

PURPOSE

The reproductive outcomes of patients with endometriosis who are infertile have attracted recent attention. We aimed to explore whether endometriosis affects endometrial receptivity by observing pregnancy outcomes following a euploid blastocyst frozen embryo transfer.

METHODS

This retrospective cohort study analyzed the data of patients with endometriosis from the reproductive hospital affiliated to Shandong University between January 2015 and December 2021. Control groups were matched using the 1:3 propensity score. The live birth, clinical pregnancy, biochemical pregnancy, clinical abortion, premature birth, and aneuploid rates were compared between the control group and endometriosis group.

RESULTS

A total of 625 patients who underwent preimplantation genetic testing (PGT) prior to embryo implantation were included in the analysis. There were no significant differences in the live birth, clinical pregnancy, biochemical pregnancy, clinical abortion, and premature birth rates between the two groups. The aneuploidy rate of blastocysts obtained from the endometriosis group was higher than that of the control group (P = 0.012).

CONCLUSION

Pregnancy outcomes using frozen embryos after PGT in patients with endometriosis did not differ from those in other women experiencing infertility. However, endometriosis may affect the quality of oocytes, resulting in a higher rate of aneuploidy.

"Are we not going too far?": Socio-ethical considerations of preimplantation genetic testing using polygenic risk scores according to healthcare professionals

The recent introduction of polygenic risk scores within preimplantation genetic testing (PGT-P) has been met with many concerns. To get more insights into the perspectives of relevant stakeholders on the socio-ethical aspects of PGT-P, an interview study with 31 healthcare professionals involved in reproductive medicine and genetics in Europe and North-America was performed. Healthcare professionals in our study were concerned that PGT-P was going too far in terms of selection, with regards to both medical conditions and non-medical traits. Healthcare professionals were worried about the ethical 'slippery slope' of PGT-P, the increasing medicalization of reproductive health, the commercial context of PGT-P, and potential stigmatization and discrimination. There were also concerns that the availability and the 'technological imperative' of PGT-P could lead to pressure and a sense of responsibility for parents to use PGT-P. Additionally, it could cause new anxieties about the child's health before the child has even been born. Since PGT-P provides polygenic risk scores before birth, the autonomy of the child has to be considered. These socio-ethical concerns heighten existing debates regarding reproductive genetic technologies and show that the specifics of PGT-P make this screening option especially ethically controversial.

PGT and deferred embryo transfer: Is blastocyst biopsy more effective than cleaved embryo biopsy?

OBJECTIVE

Blastocyst biopsy has recently been implemented in our laboratory for PGT with a "freeze all" indication. The aim of this study is to compare PGT results between embryos biopsied at the cleaved and embryos biopsied at the blastocyst stage.

STUDY DESIGN

This is a retrospective cohort study conducted from January 2017 to December 2022 in France. All couples with a "freeze all" indication the day of hCG trigerring during the study period were included in the study. Patients were retrospectively assigned in one group of two groups based on the day of embryo biopsy: the cleavage group if a blastomere biopsy was performed on day 3/4 or the blastocyst group if a trophectoderm biopsy was performed on day 5/6. We evaluated and compared the results between the two groups for biological parameters and clinical outcomes.

RESULTS

In total, 325 PGT cycles (291 patients) were included in our study. Frozen-thawed embryo transfer was performed for 285 cycles, 122 in the blastocyst group and 163 in the cleavage group. The number of biopsied embryos per cycle is significantly higher in the cleavage group with a mean of 7.2 ± 4.1 embryos biopsied per cycle vs. 2.9 ± 2.8 embryos in the blastocyst group (p < 0.001). The rate of the useful embryos was similar between the two groups with 14.6 % of frozen healthy embryos among the 1352 cleaved embryos obtained in blastocyst group, compared to 17.1 % in the cleavage group. No significant differences in clinical pregnancy rate per transfer and implantation rate were observed between the blastocyst and cleavage groups (36.4% vs. 40.4 % and 33.1% vs. 33.2 % respectively).

CONCLUSIONS

For "freeze all" PGT cycles, the day of embryo biopsy (cleaved vs blastocyst biopsy) does not impact pregnancy outcomes. Knowing how to perform embryo biopsy at different stages helps to better organize daily laboratory activity and to rescue some undiagnosed embryos after day 3 biopsy.

Should non-invasive prenatal testing be recommended for patients who achieve pregnancy with PGT?

OBJECTIVE

To determine whether non-invasive prenatal testing is an alternative testing option to preimplantation genetic testing (PGT) in pregnant patients.

METHODS

This was a retrospective study of the clinical outcomes of patients who underwent PGT and invasive or non-invasive pregnancy testing after euploid blastocyst transfer at our IVF centre between January 2017 and December 2022.

RESULTS

In total, 321 patients were enrolled in this study, 138 (43.0%) received invasive pregnancy testing, and 183 (57.0%) patients underwent non-invasive testing. The mean age of the patients in Group 2 was higher than that of the patients in Group 1 (35.64 ± 4.74 vs. 31.04 ± 4.15 years, P < 0.001). The basal LH and AMH levels were higher in Group 1 than in Group 2 (4.30 ± 2.68 vs. 3.40 ± 1.88, P = 0.003; 5.55 ± 11.22 vs. 4.09 ± 3.55, P = 0.012), but the clinical outcomes were not significantly different. Furthermore, the clinical outcomes of patients undergoing invasive testing were similar to those of patients undergoing non-invasive testing with the same PGT indication.

CONCLUSION

Our results suggest that non-invasive pregnancy testing is a suitable alternative option for detecting the foetal chromosomal status in a PGT cycle. However, the usefulness of non-invasive testing in PGT-M patients is still limited.

Development of preimplantation genetic testing for monogenic reference materials using next-generation sequencing

OBJECTIVE

Preimplantation genetic testing for monogenic disorders (PGT-M) has been used for over 20 years to detect many serious genetic conditions. However, there is still a lack of reference materials (RMs) to validate the test performance during the development and quality control of PGT-M.

METHOD

Sixteen thalassemia cell lines from four thalassemia families were selected to establish the RMs. Each family consisted of parents with heterozygous mutations for α- and/or β-thalassemia and two children, at least one of whom carried a homozygous thalassemia mutation (proband). The RM panel consisted of 12 DNA samples (parents and probands in 4 families) and 4 simulated embryos (cell lines constructed from blood samples from the four nonproband children). Four accredited genetics laboratories that offer verification of thalassemia samples were invited to evaluate the performance of the RM panel. Furthermore, the stability of the RMs was determined by testing after freeze‒thaw cycles and long-term storage.

RESULTS

PGT-M reference materials containing 12 genome DNA (gDNA) reference materials and 4 simulated embryo reference materials for thalassemia testing were successfully established. Next-generation sequencing was performed on the samples. The genotypes and haplotypes of all 16 PGT-M reference materials were concordant across the four labs, which used various testing workflows. These well-characterized PGT-M reference materials retained their stability even after 3 years of storage.

CONCLUSION

The establishment of PGT-M reference materials for thalassemia will help with the standardization and accuracy of PGT-M in clinical use.

High-resolution PGT-A results in incidental identification of patients with small pathogenic copy number variants

PURPOSE

This study aimed to evaluate whether a high-throughput high-resolution PGT-A method can detect copy number variants (CNVs) that could have clinical implications for patients and their embryos.

METHODS

A prospective analysis of PGT-A cases was conducted using a high-resolution SNP microarray platform with over 820,000 probes. Cases where multiple embryos possessed the same segmental imbalance were identified, and preliminary PGT-A reports were issued recommending either parental microarray or conventional karyotyping to identify CNVs or translocations.

RESULTS

Analysis of 6080 sequential PGT-A cases led to identification of 41 cases in which incidental findings were observed (0.7%) and parental testing was recommended. All cases, in which parental studies were completed, confirmed the original PGT-A incidental findings. In 2 of the cases, parental studies indicated a pathogenic variant with clinical implications for the associated embryos. In one of these cases, the patient was identified as a carrier of a duplication in chromosome 15q11.2:q11.2 (SNRPN + +), which is associated with autism spectrum disorder. In the second case, the patient was heterozygous positive for an interstitial deletion of 3p26.1:p26.3, which is associated with 3p deletion syndrome and had clinical implications for the patient and associated embryos. In each case, parental studies were concordant with PGT-A findings and revealed the presence of an otherwise unknown CNV.

CONCLUSION

High-throughput high-resolution SNP array-based PGT-A has the ability to detect previously unknown and clinically significant parental deletions, duplications, and translocations. The use of cost-effective SNP array-based PGT-A methods may improve the effectiveness of PGT by identifying and preventing previously unknown pathogenic CNVs in children born to patients seeking in vitro fertilization.

Preimplantation genetic testing for embryos predisposed to hereditary cancer: Possibilities and challenges

Preimplantation genetic testing (PGT), which was developed as an alternative to prenatal genetic testing, allows couples to avoid pregnancies with abnormal chromosomes and the subsequent termination of the affected fetus. Originally used for early onset monogenic conditions, PGT is now used to prevent various types of inherited cancer conditions based on the development of PGT technology, assisted reproductive techniques (ARTs), and in vitro fertilization (IVF). This review provides insights into the potential benefits and challenges associated with the application of PGT for hereditary cancer and provides an overview of the existing literature on this test, with a particular focus on the current challenges related to laws, ethics, counseling, and technology. Additionally, this review predicts the future potential applications of this method. Although PGT may be utilized to predict and prevent hereditary cancer, each case should be comprehensively evaluated. The motives of couples must be assessed to prevent the misuse of this technique for eugenic purposes, and non-pathogenic phenotypes must be carefully evaluated. Pathological cases that require this technology should also be carefully considered based on legal and ethical reasoning. PGT may be the preferred treatment for hereditary cancer cases; however, such cases require careful case-by-case evaluations. Therefore, this study concludes that multidisciplinary counseling and support for patients and their families are essential to ensure that PGT is a viable option that meets all legal and ethical concerns.

OneGene PGT: comprehensive preimplantation genetic testing method utilizing next-generation sequencing

PURPOSE

Preimplantation genetic testing for monogenic disorders (PGT-M) allows early diagnosis in embryos conceived in vitro. PGT-M helps to prevent known genetic disorders in affected families and ensures that pathogenic variants in the male or female partner are not passed on to offspring. The trend in genetic testing of embryos is to provide a comprehensive platform that enables robust and reliable testing for the causal pathogenic variant(s), as well as chromosomal abnormalities that commonly occur in embryos. In this study, we describe PGT protocol that allows direct mutation testing, haplotyping, and aneuploidy screening.

METHODS

Described PGT protocol called OneGene PGT allows direct mutation testing, haplotyping, and aneuploidy screening using next-generation sequencing (NGS). Whole genome amplification product is combined with multiplex PCR used for SNP enrichment. Dedicated bioinformatic tool enables mapping, genotype calling, and haplotyping of informative SNP markers. A commercial software was used for aneuploidy calling.

RESULTS

OneGenePGT has been implemented for seven of the most common monogenic disorders, representing approximately 30% of all PGT-M indications at our IVF centre. The technique has been thoroughly validated, focusing on direct pathogenic variant testing, haplotype identification, and chromosome abnormality detection. Validation results show full concordance with Sanger sequencing and karyomapping, which were used as reference methods.

CONCLUSION

OneGene PGT is a comprehensive, robust, and cost-effective method that can be established for any gene of interest. The technique is particularly suitable for common monogenic diseases, which can be performed based on a universal laboratory protocol without the need for set-up or pre-testing.

Islamic Perspectives on Polygenic Testing and Selection of IVF Embryos (PGT-P) for Optimal Intelligence and Other Non-Disease-Related Socially Desirable Traits

In recent years, the genetic testing and selection of IVF embryos, known as preimplantation genetic testing (PGT), has gained much traction in clinical assisted reproduction for preventing transmission of genetic defects. However, a more recent ethically and morally controversial development in PGT is its possible use in selecting IVF embryos for optimal intelligence quotient (IQ) and other non-disease-related socially desirable traits, such as tallness, fair complexion, athletic ability, and eye and hair colour, based on polygenic risk scores (PRS), in what is referred to as PGT-P. Artificial intelligence (AI) and machine learning-based analysis of big data sets collated from genome sequencing of specific human ethnic populations can be used to estimate an individual embryo's likelihood of developing such multifactorial traits by analysing the combination of specific genetic variants within its genome. Superficially, this technique appears compliant with Islamic principles and ethics. Because there is no modification of the human genome, there is no tampering with Allah's creation (taghyīr khalq Allah). Nevertheless, a more critical analysis based on the five maxims of Islamic jurisprudence (qawa'id fiqhiyyah) that are often utilized in discourses on Islamic bioethics, namely qaṣd (intention), yaqın̄ (certainty), ḍarar (injury), ḍarūra (necessity), and `urf (custom), would instead reveal some major ethical and moral flaws of this new medical technology in the selection of non-disease-related socially desirable traits, and its non-compliance with the spirit and essence of Islamic law (shariah). Muslim scholars, jurists, doctors, and biomedical scientists should debate this further and issue a fatwa on this new medical technology platform.

Polygenic embryo screening: are there potential maternal and fetal harms?

Polygenic embryo screening (PES) and its derivate the Embryo Health Score (EHS) have generated interest in both infertile and fertile populations due to their potential ability to select embryos with a reduced risk of disease and improved long-term health outcomes. Concerns have been raised regarding the potential harms of IVF itself, including possible epigenetic changes that may affect the health of the offspring in late adulthood, which are not fully captured in the EHS calculation. Knowledge of the potential impacts of the trophectoderm biopsy, which is a key component of the PES procedure, on the offsprings' health is limited by the heterogeneity of the population characteristics used in the published studies. Nonetheless, the literature suggests a possible increased risk of preterm delivery, birth defects and pre-eclampsia after trophectoderm biopsy. Overall, the risks of PES for prenatal and postnatal health remain uncertain, and further research is needed. Counselling patients regarding these risks before considering PES is important, to provide an understanding of the risks and benefits. This review aims to highlight some of these issues, the need for continued investigation in this area, and the importance of informed decision-making in the context of PES.

High sperm DNA fragmentation increased embryo aneuploidy rate in patients undergoing preimplantation genetic testing

RESEARCH QUESTION

Is high sperm DNA fragmentation (SDF) associated with a high embryonic aneuploidy rate in patients undergoing intracytoplasmic sperm injection (ICSI)-preimplantation genetic testing (PGT)?

DESIGN

This was a retrospective study of 426 couples with normal karyotypes undergoing ICSI-PGT at the authors' centre from March 2017 to March 2021. SDF was assessed using the sperm chromatin structure assay. The population was divided into low and high SDF groups according to cut-off values found by the receiver operating characteristic (ROC) curve. A 1:1 ratio propensity score matching (PSM) method was used to control for potential confounding factors, and a generalized linear mixed model was established to evaluate the relationship between SDF and the embryonic aneuploidy rate.

RESULTS

The ROC curve indicated a threshold of 30%. In total, 132 couples were included after PSM, and the high SDF group (>30%) had significantly higher SDF (40.74% ± 9.78% versus 15.54% ± 7.86%, P < 0.001) and a higher embryo aneuploidy rate (69.36% versus 53.96%, P < 0.001) compared with the low SDF group (≤30%). The two pronuclear fertilization rate, cleavage rate, rate of high-quality embryos at day 3 rate, blastocyst rate, biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, caesarean section rate, preterm birth rate, singleton rate and low birthweight rate were similar in both groups (P > 0.05). After PSM, SDF > 30% was significantly correlated with an increased embryo aneuploidy rate after adjusting for all confounding variables (adjusted odds ratio 1.70, 95% CI 1.00-2.88, P = 0.049).

CONCLUSIONS

SDF > 30% was associated with an increased embryo aneuploidy rate in couples with normal karyotypes undergoing PGT, but did not affect embryonic and clinical outcomes after transfer of euploid embryos.

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.

PGT-HLA programmes for the cure of a sick sibling: clinical strategies for this challenging search

The ultimate goal of a preimplantation genetic testing and human leukocyte antigen (PGT-HLA) matching programme is the birth of a healthy, HLA-compatible child for the treatment or cure of a sick sibling. Several authors have published successful cases of the births of children HLA-matched to siblings affected by different conditions and diseases. However, there are many reports of failed attempts. Couples seeking an HLA-matched sibling for their affected child look for positive outcomes in the shortest possible time. Nevertheless, there is no published consensus or guidelines with recommendations for these cases. Here, the authors aimed to analyse different approaches for these programmes, highlighting the most promising strategies for the families and fertility units. Furthermore, the authors mention a successful case of a PGT-HLA matching programme after a previous failed attempt following the strategies proposed. Which is the most cost-effective and time-efficient approach in a PGT-HLA matching programme?

Role of genetic analysis of products of conception and PGT in managing early pregnancy loss

This article considers the addition of comprehensive 24-chromosomal microarray (CMA) analysis of products of conception (POC) to a standard evaluation for recurrent pregnancy loss (RPL) to help direct treatment towards expectant management versus IVF with preimplantation genetic testing for aneuploidies (PGT-A). The review included retrospective data from 65,333 miscarriages, a prospective evaluation of 378 couples with RPL who had CMA testing of POC and the standard workup, and data from an additional 1020 couples who were evaluated for RPL but did not undergo CMA testing of POC. Aneuploidy in POC explained the pregnancy loss in 57.7% (218/378) of cases. In contrast, the full RPL evaluation recommended by the American Society for Reproductive Medicine identified a potential cause in only 42.9% (600/1398). Combining the data from the RPL evaluation and the results of genetic testing of POC provides a probable explanation for the loss in over 90% (347/378) of women. Couples with an unexplained loss after the standard evaluation with POC aneuploidy accounted for 41% of cases; PGT-A may be considered after expectant management. Conversely, PGT-A would have a limited role in those with a euploid loss and a possible explanation after the standard workup. Categorizing a pregnancy loss as an explained versus unexplained loss after the standard evaluation combined with the results of CMA testing of POC may help identify patients who would benefit from expectant management versus PGT-A.

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 single gene or chromosomal diseases. Preimplantation genetic testing for polygenic disease risk (PGT-P) is the latest development in the field. It is known that polygenic diseases usually have the characteristics of high incidence, late onset, affecting the quality of life and mental health of patients. On the basis of the development of artificial intelligence and genetic detection technology, PGT-P can analyze genetic material, calculate polygenic risk score turning into incidence probability. Embryos with relatively low incidence probability can be screened for transfer, so as to reduce the possibility of offspring suffering from the disease in the future, which has significant clinical and social significance. At present, PGT-P has been applied clinically and made phased progress at home and abroad. At the same time, as a developing technology, PGT-P still has some technical defects, unstable results, environmental influences and racial differences cannot be ruled out. From the perspective of ethics, if the screening indications are not strictly regulated, it is likely to cause new social problems. In this paper, we review the technical composition and recent progress of PGT-P, and put forward the prospect of its future development, especially how to establish a complete and suitable screening model for Chinese population.

Clinical practice and outcomes of preimplantation genetic testing for CMT1A using a novel direct detection method

Background

Charcot-Marie-Tooth type 1A (CMT1A), the most frequent type of Charcot-Marie-Tooth disease, is mainly caused by a 1.4-Mb duplication containing the PMP22 gene. There is no effective treatment other than general supportive care and symptomatic treatment. Preimplantation genetic testing for monogenic defects (PGT-M) is an alternative approach for obtaining healthy babies.

Methods

A new technology and analysis method based on next-generation sequencing (NGS) was developed to detect duplication mutations directly. Simultaneously, aneuploidy and linkage analyses were performed to achieve a comprehensive and accurate embryo diagnosis.

Results

Eight couples were recruited in this study; PMP22 duplication was validated in seven couples, and PMP22 splicing mutation was found in one. Forty-five embryos from 12 PGT cycles were successfully detected using this novel method. The direct detection results for all embryos were consistent with the linkage analyses, suggesting a 100 % accuracy rate, and the aneuploidy rate of the biopsied blastocysts was 33.3 %. Eventually, 18 of the 45 diagnosed embryos were deemed suitable for transfer. Four healthy babies from three families were delivered and their genetic status confirmed by amniocentesis. Additionally, there were no adverse effects of anesthesia or increased pregnancy complications during PGT-M in female patients with CMT1A.

Conclusions

This study provided a simple, reliable, and efficient method that can directly detect PMP22 mutations based on NGS data and does not require positive family members. A clinical workflow for CMT1A interruption in the offspring before embryo implantation is also summarized.

Single closed-tube quantitative real-time PCR assay with dual-labelled probes for improved sex determination of equine embryos

In addition to fulfilling many breeders' curiosity, equine embryonic sex determination can have a profound commercial impact. However, the application of currently described assays for equine embryonic sexing has rendered variable diagnosis and validation rates, with sensitivity being the main problem. In addition, while pregnancy results of in vivo-flushed equine embryos following a needle aspiration biopsy equal those of non-biopsied embryos, the effect on in vitro-produced embryos is unknown. Here, we aimed to develop a highly sensitive and specific assay for equine sex determination that can be directly performed on few embryonic cells, and to test the effect of a needle aspiration biopsy on the viability of the in vitro-produced embryo. To this end, a multiplex quantitative real-time PCR (qPCR) assay with dual-labelled probes was designed to allow the simultaneous generation of both male-specific and control fragments in a single closed-tube reaction, avoiding potential sample loss or contamination. To improve sensitivity, multicopy and polymeric genes were chosen to be specifically amplified, i.e., eight copies of Y-chromosomal ETSTY5 as male-specific and four autosomal UBC monomers as control fragment. Specificity was enhanced by the equine-specific character of ETSTY5 and by using dual-labelled probes. The assay was optimised with equine male and female genomic DNA and demonstrated a 100% accuracy and a >95% qPCR efficiency down to 10 pg of DNA. The assay was subsequently applied to determine the sex of 44 in vitro-produced embryos, collecting trophectoderm biopsies by means of a needle aspiration biopsy and herniating cells. Of all trophectoderm biopsies and herniating cell samples (n = 54), 87% could be diagnosed. Assay results were validated on a second sample obtained from the biopsied embryo (n = 18) or, by ultrasound-based sex determination of the foetus (n = 7) following the transfer of the biopsied embryo to a recipient mare, with about half of the embryos being fillies and colts. The needle aspiration biopsy procedure did not impair initial pregnancy rate or early pregnancy losses as compared to non-biopsied embryos. In conclusion, we report a safe, reliable, fast, and cost-effective assay for equine sex determination which was validated for the sex determination of in vitro-produced embryos based on few embryonic cells, and needle aspiration biopsy did not impair the embryo's viability. The assay and safe biopsy strategy hold potential for other applications.

Meiotic and mitotic aneuploidies drive arrest of in vitro fertilized human preimplantation embryos

BACKGROUND

The high incidence of aneuploidy in early human development, arising either from errors in meiosis or postzygotic mitosis, is the primary cause of pregnancy loss, miscarriage, and stillbirth following natural conception as well as in vitro fertilization (IVF). Preimplantation genetic testing for aneuploidy (PGT-A) has confirmed the prevalence of meiotic and mitotic aneuploidies among blastocyst-stage IVF embryos that are candidates for transfer. However, only about half of normally fertilized embryos develop to the blastocyst stage in vitro, while the others arrest at cleavage to late morula or early blastocyst stages.

METHODS

To achieve a more complete view of the impacts of aneuploidy, we applied low-coverage sequencing-based PGT-A to a large series (n = 909) of arrested embryos and trophectoderm biopsies. We then correlated observed aneuploidies with abnormalities of the first two cleavage divisions using time-lapse imaging (n = 843).

RESULTS

The combined incidence of meiotic and mitotic aneuploidies was strongly associated with blastocyst morphological grading, with the proportion ranging from 20 to 90% for the highest to lowest grades, respectively. In contrast, the incidence of aneuploidy among arrested embryos was exceptionally high (94%), dominated by mitotic aneuploidies affecting multiple chromosomes. In turn, these mitotic aneuploidies were strongly associated with abnormal cleavage divisions, such that 51% of abnormally dividing embryos possessed mitotic aneuploidies compared to only 23% of normally dividing embryos.

CONCLUSIONS

We conclude that the combination of meiotic and mitotic aneuploidies drives arrest of human embryos in vitro, as development increasingly relies on embryonic gene expression at the blastocyst stage.

Embryo ploidy in vitrified versus fresh oocytes: Is there a difference?

PURPOSE

To evaluate embryo ploidy in a cohort of patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) with vitrified oocytes compared to fresh oocytes.

METHODS

Patients who underwent their first autologous oocyte vitrification and warming followed by in vitro fertilization (IVF) and trophectoderm biopsy for PGT-A between 1/1/2017 and 12/31/2021 at a single academic institution were included. Patients were compared 1:3 to age-matched controls who underwent their first IVF cycle with fresh oocytes and subsequent trophectoderm biopsy for PGT-A. The primary outcome was the proportions of euploid, mosaic, and aneuploid embryos between those using vitrified versus fresh oocytes.

RESULTS

117 patients who cryopreserved a total of 1,272 mature oocytes were included in the study and were matched with 351 controls using fresh oocytes. The average age was 36.9 ± 2.6 years, and the median interval between oocyte vitrification and warming was 38 months. There were similar numbers of mature oocytes (10.9 ± 4.9 vs. 11.1 ± 6.3, P = .67), fertilized oocytes (7.8 ± 4.0 vs. 8.7 ± 5.5, P = .10), and blastocysts per patient (5.1 ± 3.1 vs. 5.8 ± 4.3, P = .10) between those using vitrified versus fresh oocytes. In terms of embryo ploidy results, there were no statistically significant differences in rates of euploidy (40.1% vs. 41.6%), mosaicism (15.7% vs. 12.0%), or aneuploidy (44.3% vs. 46.4%) (P = .06) between the two groups.

CONCLUSIONS

Oocyte vitrification with subsequent warming, fertilization, and trophectoderm biopsy for PGT-A was not associated with adverse chromosomal competence when compared to age-matched controls utilizing fresh oocytes.

Development of preimplantation genetic testing for monogenic diseases in China

Preimplantation genetic testing for monogenic diseases (PGT-M) can effectively interrupt the transmission of genetic diseases from parents to the offspring before pregnancy. In China, there are over ten million individuals afflicted with monogenic disorders. This literature review summarizes the development of PGT-M in China for the past 24 years, covering the general steps such as the indications and contraindications, genetic and reproductive counselling, biopsy methods, detecting techniques and strategies during PGT-M application in China. The ethical considerations of PGT-M are also be emphasized, including sexual selection, transferring for mosaic embryos, the three-parent baby, and the different opinions for serious adult-onset conditions. Some key policies of the Chinese government for the application of PGT-M are also considered. Methods for regulation of this technique, as well as specific management to increase the accuracy and reliability of PGT-M, are regarded as priority issues in China. The third-generation sequencing and variants testing from RNA level, and non-invasive preimplantation genetic testing using blastocoel fluid and free DNA particles within spent blastocyst medium might be potential techniques and strategies for PGT-M in future.

Outcomes of random-start letrozole protocol with PGT-A in women with breast cancer undergoing fertility preservation

PURPOSE  : To compare the cycle characteristics and outcomes of random-start-controlled ovarian stimulation (RSCOS) protocols to the outcomes of standard-start-controlled ovarian stimulation (SSCOS) cycles and to report the utility of PGT-A in these cycles.

METHODS

One hundred and seventeen who underwent SSCOS and 39 who underwent RSCOS for oocyte and/or embryo cryopreservation before breast cancer chemotherapy were retrospectively evaluated. Mean number of embryos and blastocyst euploidy rates were the main outcome measures.

RESULTS

A majority of RSCOS cycles were initiated in the luteal phase (66.6% luteal vs. 33.3% follicular). While the total dose of gonadotropins was significantly higher in the RSCOS (3720.8 ± 1230.0 vs. 2345.1 ± 803.6 IU; P < 0.001), the mean number of mature oocytes and embryos was similar to SSCOS. However, there was a trend for a higher number of mean embryos with luteal start RSCOS (6.9 ± 2.7 in late follicular start vs. 9.4 ± 4.2 in luteal start, P = 0.08). PGT-A was performed in 48% of the cases that underwent embryo cryopreservation in RSCOS (12 women, mean age = 35.3 ± 4.1; 87 blastocysts), revealing a euploidy rate of 36.2 ± 22.3% per patient. This rate was comparable to a 45% aneuploidy rate from similarly aged published data. Of the 7 RSCOS patients who returned for frozen embryo transfer, 5 delivered and one has an ongoing pregnancy, while in SSCOS, 18 out of 40 cycles resulted in live birth.

CONCLUSION

Our data suggests that RSCOS fertility preservation cycle outcomes are similar to those with SSCOS and result in age-appropriate euploidy rates.

Impact of male age on paternal aneuploidy: single-nucleotide polymorphism microarray outcomes following blastocyst biopsy

RESEARCH QUESTION

Does advanced paternal age (APA; ≥40 years) contribute to a higher incidence of paternal origin aneuploidy in preimplantation embryos?

DESIGN

This was a multicentre retrospective study of single-nucleotide polymorphism (SNP) microarray (Natera and Karyomapping) preimplantation genetic testing (PGT) outcomes of blastocyst-stage embryos. Whole-chromosome aneuploidy analysis was performed on 2409 embryos from 389 male patients undertaking 681 assisted reproductive technology (ART) cycles between 2012-2021. Segmental aneuploidy analysis was performed on 867 embryos from 140 men undertaking 242 ART cycles between 2016-2021. Embryos were grouped based on paternal age at sperm collection: <35, 35-39 and ≥40 years. Paternal and maternal origin aneuploidy rates were compared between groups using chi-squared and/or Fisher's exact tests.

RESULTS

There was no significant difference across groups in paternal origin whole-chromosome aneuploidy rate, overall (P=0.7561) or when segregated by type (trisomy and monosomy: P=0.2235 and 0.8156) or complexity (single versus 2, 3 or ≥4 aneuploidies: P=0.9733, 0.7517, 0.669 and 0.1481). Conversely, maternal origin whole-chromosome aneuploidy rate differed across groups (P<0.0001) in alignment with differing mean maternal age (P<0.001). Paternal origin deletions were 2.9-fold higher than maternal origin deletions (P=0.0084), independent of age stratification. No significant difference in paternal origin deletions was observed with APA ≥40 compared with the younger age groups (4.8% versus 2.5% and 2.8%, P=0.5292). Individual chromosome aneuploidy rates were too low to perform statistical comparisons.

CONCLUSIONS

No significant association was found between APA and the incidence of paternal origin aneuploidy in preimplantation embryos, irrespective of type or complexity. Thus, APA may not be an indication for PGT.

Preimplantation genetic testing for aneuploidy helps to achieve a live birth with fewer transfer cycles for the blastocyst FET patients with unexplained recurrent implantation failure

PURPOSE

This retrospective cohort study aimed to investigate the value of preimplantation genetic testing for aneuploidy (PGT-A) as a screening test for patients suffering from unexplained recurrent implantation failure (RIF).

METHODS

After screening patients in one reproductive medicine center, twenty-nine, forty-nine and thirty-eight women (< 40 years old) who had suffered unexplained RIF with PGT-A, or RIF without PGT-A, or no RIF with PGT-A were included. The clinical pregnancy rate and live birth rate per transfer, the conservative and optimal cumulative clinical pregnancy rates (CCPR) and live birth rates (CLBR) after three blastocyst FETs were analyzed.

RESULTS

The live birth rate per transfer was significantly higher in the RIF + PGT-A group than that in the RIF + NO PGT-A group (47.6% vs. 24.6%, p = 0.014). After 3 cycles of FET, RIF + PGT-A group had significantly higher conservative CLBR and optimal CLBR compared to the RIF + NO PGT-A group (69.0% vs. 32.7%, p = 0.002 and 73.7% vs. 57.5%, p = 0.016), but had similar conservative and optimal CLBRs compared to the NO RIF + PGT-A group. The number of FET cycles required when half women achieved a live birth was 1 in the PGT-A group and 3 in RIF + NO PGT-A group. The miscarriage rates were not different between the RIF + PGT-A and RIF + NO PGT-A, RIF + PGT-A and NO RIF + PGT-A groups.

CONCLUSION

PGT-A did be superior in reducing the number of transfer cycles required to achieve a similar live birth rate. Further studies to identify the RIF patients who would benefit most from PGT-A are necessary.

ART in Latin America: the Latin American Registry, 2020

RESEARCH QUESTION

What was the utilization, effectiveness and safety of assisted reproductive technology (ART) in Latin America during 2020?

DESIGN

Retrospective collection of multinational data on ART performed by 188 institutions in 16 countries.

RESULTS

Overall, 87,732 initiated cycles resulted in 12,778 deliveries and 14,582 births. The major contributors were Brazil (46.0%), Mexico (17.0%) and Argentina (16.8%). However, the highest utilization (cycles/million inhabitants) was Uruguay with 558, followed by Argentina with 490 and Panama with 425 cycles/million. Globally, women aged ≥40 years increased to 34% while women ≤34 dropped to 24.7%. After removing freeze-all cycles, the delivery rate per oocyte retrieval was 14.8% for intracytoplasmic sperm injection and 15.6% for IVF. Single-embryo transfer (SET) represented 38.3% of all fresh transfers, with delivery rate per transfer of 20.0%; this increased to 32.4% for elective SET (eSET) and 34.2% for blastocyst eSET, compared with blastocyst elective double embryo transfer (eDET) of 37.9%. However, multiple births increased from 1% in eSET to 30.5% in eDET. Perinatal mortality increased from 7.7‰ in singletons to 24.4‰ in twins and 64.0‰ in triplets. Frozen embryo transfer (FET) represented 66.6% of all transfers, with a delivery rate/transfer of 29.0%, significantly higher than 23.9% after fresh transfers at all ages (P < 0.0001). Preimplantation genetic testing, reported in 8920 cycles, significantly improved delivery rate and decreased miscarriage rates at all ages (P ≤ 0.041), including oocyte donation (P = 0.002). Endometriosis was diagnosed in 28.3% of cases. The delivery rate in 5779 women after removal of peritoneal endometriosis was significantly better than tubal and endocrine factors in women aged 35-39 (P = 0.0004) and women aged ≥40 (P = 0.0353).

CONCLUSIONS

Systematic collection and analysis of big data in a south-south cooperation model allow regional growth by implementing evidence-based reproductive decisions.

Adverse maternal and neonatal outcomes of preimplantation genetic testing with trophectoderm biopsy: a retrospective cohort study of 3373 intracytoplasmic sperm injection single frozen-thawed blastocyst transfer cycles

PURPOSE

To investigate whether trophectoderm biopsy increases the risk of adverse maternal and neonatal outcomes in intracytoplasmic sperm injection (ICSI) single frozen-thawed blastocyst transfer cycles.

METHODS

This respective cohort study enrolled 3373 ICSI single frozen-thawed blastocyst transfer cycles with and without trophectoderm biopsy. Statistical methods including univariate logistic regression analysis, multivariate logistic regression analysis, and stratified analyses were performed to explore the impact of trophectoderm biopsy on adverse maternal and neonatal outcomes.

RESULTS

The rates of adverse maternal and neonatal outcomes were comparable between the two groups. Univariate analysis showed that the live birth rate (45.15% vs. 40.75%; P = 0.010) in the biopsied group was statistically higher than that in the unbiopsied group, and the rates of miscarriage (15.40% vs. 20.00%; P = 0.011) and birth defects (0.58% vs. 2.16%; P = 0.007) were statistically lower in the biopsied group. After adjusting for confounding factors, the rates of miscarriage (aOR = 0.74; 95% CI = 0.57-0.96; P = 0.022) and birth defects (aOR = 0.24, 95% CI = 0.08-0.70, P = 0.009) in the biopsied group were significantly lower than those in the unbiopsied group. Stratified analyses showed that the birth defects rate after biopsy was significantly reduced in the subgroups of age < 35 years old, BMI ≥ 24 kg/m², artificial cycle with downregulation, poor-quality blastocysts, and Day 5 poor-quality blastocysts.

CONCLUSION

Preimplantation genetic testing (PGT) with trophectoderm biopsy does not increase the risk of adverse maternal and neonatal outcomes in ICSI single frozen-thawed blastocyst transfer cycles, and PGT can effectively reduce the rates of miscarriage and birth defects.

Mitochondrial DNA quantification correlates with the developmental potential of human euploid blastocysts but not with that of mosaic blastocysts

PURPOSE

We aimed to study the association between adjusted mtDNA levels in human trophectoderm biopsy samples and the developmental potential of euploid and mosaic blastocysts.

METHODS

We analyzed relative mtDNA levels in 2,814 blastocysts obtained from 576 couples undergoing preimplantation genetic testing for aneuploidy from June 2018 to June 2021. All patients underwent in vitro fertilization in a single clinic; the study was blinded-mtDNA content was unknown at the time of single embryo transfer. The fate of the euploid or mosaic embryos transferred was compared with mtDNA levels.

RESULTS

Euploid embryos had lower mtDNA than aneuploid and mosaic embryos. Embryos biopsied on Day 5 had higher mtDNA than those biopsied on Day 6. No difference was detected in mtDNA scores between embryos derived from oocytes of different maternal ages. Linear mixed model suggested that blastulation rate was associated with mtDNA score. Moreover, the specific next-generation sequencing platform used have a significant effect on the observed mtDNA content. Euploid embryos with higher mtDNA content presented significantly higher miscarriage rates and lower live birth rates, while no significant difference was observed in the mosaic cohort.

CONCLUSION

Our results will aid in improving methods for analyzing the association between mtDNA level and blastocyst viability.

Clinical application of next generation sequencing-based haplotype linkage analysis in the preimplantation genetic testing for germline mosaicisms

BACKGROUND

Preimplantation genetic testing (PGT) for monogenic disorders (PGT-M) for germline mosaicism was previously highly dependent on polymerase chain reaction (PCR)-based directed mutation detection combined with linkage analysis of short tandem repeats (STRs). However, the number of STRs is usually limited. In addition, designing suitable probes and optimizing the reaction conditions for multiplex PCR are time-consuming and laborious. Here, we evaluated the effectiveness of next generation sequencing (NGS)-based haplotype linkage analysis in PGT of germline mosaicism.

METHODS

PGT-M with NGS-based haplotype linkage analysis was performed for two families with maternal germline mosaicism for an X-linked Duchenne muscular dystrophy (DMD) mutation (del exon 45-50) or an autosomal TSC1 mutation (c.2074C > T). Trophectoderm biopsy and multiple displacement amplification (MDA) were performed for a total of nine blastocysts. NGS and Sanger sequencing were performed in genomic DNA of family members and embryonic MDA products to detect DMD deletion and TSC1 mutation, respectively. Single nucleotide polymorphism (SNP) sites closely linked to pathogenic mutations were detected with NGS and served in haplotype linkage analysis. NGS-based aneuploidy screening was performed for all embryos to reduce the risk of pregnancy loss.

RESULTS

All nine blastocytes showed conclusive PGT results. Each family underwent one or two frozen-thawed embryo transfer cycles to obtain a clinical pregnancy, and the prenatal diagnosis showed that the fetus was genotypically normal and euploid for both families.

CONCLUSIONS

NGS-SNP could effectively realize PGT for germline mosaicism. Compared with PCR-based methods, the NGS-SNP method with increased polymorphic informative markers can achieve a greater diagnostic accuracy. Further studies are warranted to verify the effectiveness of NGS-based PGT of germline mosaicism cases in the absence of surviving offsprings.

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.

Sperm deoxyribonucleic acid fragmentation index at the time of intracytoplasmic sperm injection and standard in vitro fertilization is correlated with lower fertilization but not with blastocyst genetic diagnosis

Objective

To determine the effects of sperm deoxyribonucleic acid (DNA) fragmentation at the time of fertilization on in vitro fertilization (IVF) outcomes and genetic diagnosis using next generation sequencing.

Design

Prospective double-blinded study.

Setting

Private Clinic.

Patients

Couples (n = 150).

Intervention

In vitro fertilization with preimplantation genetic testing for aneuploidy and sperm DNA fragmentation assay, as in sperm chromatin structure assay the day of retrieval.

Main Outcome Measures

Laboratory outcomes are listed in the results section. Statistical analysis was performed using JMP, XYLSTAT, and STATA version 15.

Results

The sperm DNA fragmentation index (DFI) in the neat ejaculate did not predict fertilization rate, quality, blastulation, or genetic diagnosis. No statistically significant results were obtained comparing <15% with >15%, <20% with >20%, <30% with >30% except for DFI. No statistically significant differences in oocyte source age or male age were observed. No statistically significant differences comparing <15% with >15%, <20% with >20%, <30% with >30% DFI at the time of standard IVF or intracytoplasmic sperm injection (ICSI) were observed for % euploid, aneuploid, mosaic, blastulation, biopsied, or D5/total biopsied. The DFI of >15% had more good quality D3 embryos than the <15% group, as did the >20% group compared with the <20% group. The ICSI fertilization was significantly higher in all 3 lower percentage groups compared with the higher counterpart. Standard IVF had significantly more blastocysts/fertilized suitable for biopsy and more D5/total number biopsied than ICSI embryos despite no difference in DFI.

Conclusions

The DFI at fertilization is correlated with decreased fertilization for ICSI and IVF.

PGT-A improved singleton live birth rate among all age groups of women who underwent elective single blastocyst transfer: a single-centre retrospective study

PURPOSE

This study assessed the difference in singleton live birth rate (SLBR) between preimplantation genetic testing for aneuploidy (PGT-A) and non-PGT in patients undergoing elective single frozen blastocyst transfer (eSFBT).

METHODS

This retrospective cohort study evaluated 10,701 cycles of eSFBT, including PGT-A (n = 3125) and non-PGT (n = 7576). Cycles were further stratified according to age at retrieval. The main outcome was SLBR; secondary outcomes were clinical pregnancy, conception rates, and multiple live birth rate. Confounders were adjusted using multivariable logistic regression models, and the trend test was performed using the general linear model.

RESULTS

SLBR was negatively correlated with age in the non-PGT group (p-trend < 0.001) but not in PGT-A group (p-trend = 0.974). Stratified by the age, SLBR were significantly different between two groups except for the 20-24-year-old group: PGT-A vs non-PGT group in 20-24, 25-29, 30-34, 35-39 and ≥ 40-year-old subgroups were, 53.5% vs 53.2%, 53.5% vs 48.0%, 53.5% vs 43.1%, 53.3% vs 32.5%, and 42.9% vs 17.6%, respectively. In addition, after adjusting for potential confounders, SLBR still remained significantly different in all age groups except in the youngest quartile (PGT-A vs non-PGT group, 20-24: adjusted odds ratio (aOR), 1.33, 95% CI, 0.92-1.92, p = 0.129; 25-29: aOR, 1.32, 95% CI, 1.14-1.52, p < 0.001; 30-34: aOR, 1.91, 95% CI, 1.65-2.20, p < 0.001; 35-39: aOR, 2.50, 95% CI, 1.97-3.17, p < 0.001; ≥ 40: aOR, 3.54, 95% CI, 1.66-7.55, p = 0.001).

CONCLUSION

PGT-A might improve SLBR among all age groups and play an increasingly important role in SLBR in older patients who underwent eSFBT.

Indications and management of preimplantation genetic testing for monogenic conditions: a committee opinion

This statement is offered to update and expand on the prior American Society for Reproductive Medicine preimplantation genetic testing (PGT) opinion, elucidate the current clinical and technical complexities specific to PGT for monogenic conditions, assist providers in supporting patient understanding of and access to this technology, and offer considerations for the development of future clinical and laboratory guidelines on PGT for monogenic conditions.

Knowledge, acceptability and personal attitude toward pre-implantation 1 genetic testing (PGT) and pre-natal diagnosis (PND) for females carrying BRCA pathogenic variant according to fertility preservation experience

PURPOSE

Preimplantation genetic testing (PGT-M) and prenatal diagnosis (PND) followed by medical termination of pregnancy when the fetus is affected are two procedures developed to avoid the transmission of a severe hereditary disease which can be proposed to females that carried BRCA pathogenic variants. These females can also be offered fertility preservation (FP) when diagnosed with cancer or even before a malignancy occurs. The aim of the study was to evaluate the acceptability and personal attitude of women carrying a BRCA mutation toward techniques that can prevent BRCA transmission to their progeny.

METHODS

Female mutated for BRCA1 or BRCA2 were invited to complete an online survey of 49 queries anonymously between June and August 2022.

RESULTS

A total of 87 participants responded to the online survey. Overall, 86.2% of women considered that PGT-M should be proposed to all BRCA mutation carriers regardless of the severity of the family history, and 47.1% considered or would consider PGT-M for themselves. For PND, these percentages were lower reaching 66.7% and 29.9%, respectively. Females with personal history of breast cancer or FP achievement were more prone to undergo PND for themselves despite the overall acceptability of this procedure. Among the subgroup who had undergone FP (n = 58), there was no significant difference in acceptance of principle and personal attitude toward PGT-M and PND compared to the group without FP.

CONCLUSION

BRCA pathogenic variants female carriers do need information about reproductive issues, even if they are not prone to undergo PGT-M nor PND for themselves.

TRIAL REGISTRATION NUMBER

N/A.

Cost-effectiveness of preimplantation genetic testing for aneuploidy for women with subfertility in China: an economic evaluation using evidence from the CESE-PGS trial

BACKGROUND

There are a large number of infertile couples in China, but its treatment is notoriously expensive and not currently covered by insurance. The utility of preimplantation genetic testing for aneuploidy as an adjunct to in vitro fertilization has been debated.

OBJECTIVE

To investigate the cost-effectiveness of preimplantation genetic testing for aneuploidy (PGT-A) versus conventional technology in in vitro fertilization (IVF) from the perspective of the healthcare system in China.

METHODS

Following the exact steps in the IVF protocol, a decision tree model was developed, based on the data from the CESE-PGS trial and using cost scenarios for IVF in China. The scenarios were compared for costs per patient and cost-effectiveness. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to confirm the robustness of the findings.

MAIN OUTCOME MEASURES

Costs per live birth, Costs per patient, Incremental cost-effectiveness for miscarriage prevention.

RESULTS

The average costs per live birth of PGT-A were estimated as ¥39230.71, which is about 16.8% higher than that of the conventional treatment. Threshold analysis revealed that PGT-A would need to increase the pregnancy rate of 26.24-98.24% or a cost reduction of ¥4649.29 to ¥1350.71 to achieve the same cost-effectiveness. The incremental costs per prevented miscarriage was approximately ¥45600.23. The incremental cost-effectiveness for miscarriage prevention showed that the willingness to pay would be ¥43422.60 for PGT-A to be cost-effective.

CONCLUSION

The present cost-effectiveness analysis demonstrates that embryo selection with PGT‑A is not suitable for routine applications from the perspective of healthcare providers in China, given the cumulative live birth rate and the high costs of PGT‑A.

Blocker displacement amplification-based genetic diagnosis for autosomal dominant polycystic kidney disease and the clinical outcomes of preimplantation genetic testing

OBJECTIVE

Given that the molecular diagnosis of autosomal dominant polycystic kidney disease (ADPKD) is complicated, we aim to apply blocker displacement amplification (BDA) on the mutational screening of PKD1 and PKD2.

METHODS

A total of 35 unrelated families with ADPKD were recruited from the Center for Reproductive Medicine, Women and Children's Hospital of Chongqing Medical University (Chongqing, China), from October 2018 to October 2021. Long-range PCR followed by next-generation sequencing were applied for resequencing of PKD1 and PKD2, and the putatively disease-causative variants were verified with BDA. The effects of ADPKD on male and female infertility and the factors influencing the clinical outcomes of preimplantation genetic testing (PGT) for ADPKD were investigated.

RESULTS

A total of 26 PKD1 variants and 5 PKD2 variants were identified, of which 13 were newly discovered. The BDA system worked effectively for eliminating the interference of pseudogenes in genetic testing of PKD1 (1-33 exons) with different concentrations of genome DNA. The females with ADPKD have no specific infertility factors, while 68.2% of the affected men were with abnormal sperm concentration and/or motility with an indefinite genotype-phenotype relationship. As for PGT, the fertilization rate of couples with the male partner having ADPKD was relatively lower compared to those with the female partner being affected. The ADPKD patients receiving PGT usually achieved high rates of live births.

CONCLUSION

These findings expanded the variant spectrum of PKD genes and emphasized the application prospect of blocker displacement amplification on PKD1-related genetic diagnosis.

Does smooth endoplasmic reticulum aggregation in oocytes impact the chromosome aneuploidy of the subsequent embryos? A propensity score matching study

BACKGROUND

The appearance of smooth endoplasmic reticulum aggregation (SERa) is one of the most common dysmorphic phenotypes of oocytes, however, the impact of SERa occurrence on in vitro fertilization (IVF) outcomes is controversial. This study aimed to investigate the impact of SERa in oocytes on the aneuploidy of the subsequent embryos in IVF.

METHODS

In this retrospective cohort study, a total of 114 intracytoplasmic sperm injection (ICSI) cycles with the appearance of SERa undergoing preimplantation genetic testing for aneuploidy (PGT-A) were enrolled, and among them there were 323 SERa(+) oocytes and 1253 sibling unaffected oocytes. The 907 PGT-A cycles without SERa during the same period were enrolled as controls. A propensity score matching of 1:1 ratio between these two groups resulted in 113 matched cycles. The outcome parameters between the SERa(+) cycles/oocytes and the controls were compared. IVF laboratory outcomes, PGT-A outcomes, and clinical and neonatal outcomes were the main outcomes.

RESULTS

Increased abnormal fertilization rate and reduced blastocyst formation rate can be observed in both SERa(+) cycles and oocytes, some other parameters on developmental potential, such as available embryo rate at Day 3 and available blastocyst rate, were also impaired in the case of SERa occurrences. Among the 910 blastocysts for PGT-A, the percentage of euploid embryos was similar between the matched cohorts, while an unpredicted increase of the proportions of euploid in the SERa(+) oocytes, compared to the SERa(-) oocytes. Moreover, there was no significance in terms of clinical and neonatal outcomes, such as implantation rate, biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, and live birth rate, regardless of the presence of SERa in cycles and oocytes.

CONCLUSIONS

The appearance of SERa within mature oocytes has no significant impact on the aneuploidy of subsequent blastocysts. It is recommended to utilize these oocytes, especially for those with few oocytes or advanced maternal age, which is likely to increase the cumulative pregnancy rate. This study may offer evidence to assist embryologists to make clinical decisions concerning SERa(+) oocytes more consciously and rationally.