Updates in preimplantation genetic testing (PGT)

Preimplantation genetic testing (PGT) involves taking a biopsy of an early embryo created through in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Genetic testing is performed on the biopsy, in order to select which embryo to transfer. PGT began as an experimental procedure in the 1990s, but is now an integral part of assisted human reproduction (AHR). PGT allows for embryo selection which can reduce the risk of transmission of inherited disease and may reduce the chance of implantation failure and pregnancy loss. This is a rapidly evolving area, which raises important ethical issues. This review article aims to give a brief history of PGT, an overview of the current evidence in PGT along with highlighting exciting areas of research to advance this technology.

Preimplantation genetic testing for aneuploidy in unexplained recurrent pregnancy loss: a systematic review and meta-analysis

IMPORTANCE

Preimplantation genetic testing for aneuploidy (PGT-A) to deselect aneuploid embryos in assisted reproductive technology (ART) treatment cycles may hold promise by augmenting pregnancy rates per transfer and reducing pregnancy loss rates for patients with unexplained recurrent pregnancy loss (RPL).

OBJECTIVE

To explore effectiveness of PGT-A in managing unexplained RPL by evaluating several key aspects: the likelihood of live birth in a subsequent spontaneous pregnancy, whether women with unexplained RPL have a higher rate of aneuploidy, whether euploid blastocysts offer comparable live birth rate (LBR) in patients with unexplained RPL, whether the endometrium is less selective in unexplained RPL loss, and whether PGT-A increases the LBR or reduces pregnancy losses until delivery.

DATA SOURCES

PubMed and Cochrane Library databases were searched from inception until June 2024.

STUDY SELECTION AND SYNTHESIS

Studies involving patients with ≥2 unexplained RPL who underwent ART with or without PGT-A or expectant management were included.

MAIN OUTCOME MEASURES

The primary outcome measure was the LBR. Secondary outcome measures were aneuploidy rate, clinical pregnancy rate, and clinical pregnancy loss rate.

RESULTS

Whether couples with unexplained RPL have higher embryo aneuploidy rates remains equivocal. Euploid blastocyst transfers yielded comparable clinical pregnancy loss rate (odds ratio [OR], 1.10; 95% confidence interval [CI], 0.57-2.13) and LBR (OR, 1.04; 95% CI, 0.74-1.44) in patients with and without unexplained RPL. Comprehensive chromosome analysis of products of conception shows similar aneuploidy rates between patients with and without RPL and does not support the less selective endometrium hypothesis. Preimplantation genetic testing for aneuploidy decreased clinical pregnancy loss rate (OR, 0.42; 95% CI, 0.27-0.67) and enhanced LBR per transfer (OR, 2.17; 95% CI, 1.77-2.65) and LBR per patient (OR, 1.85; 95% CI, 1.18-2.91) in patients with unexplained RPL.

CONCLUSION AND RELEVANCE

Current low-quality evidence suggests that PGT-A enhances LBR per transfer and per patient in unexplained RPL. Well-designed randomized controlled trials comparing ART with PGT-A vs. expectant management for unexplained RPL are warranted.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42021291546.

Factors affecting biochemical pregnancy loss (BPL) in preimplantation genetic testing for aneuploidy (PGT-A) cycles: machine learning-assisted identification

PURPOSE

To determine the factors influencing the likelihood of biochemical pregnancy loss (BPL) after transfer of a euploid embryo from preimplantation genetic testing for aneuploidy (PGT-A) cycles.

METHODS

The study employed an observational, retrospective cohort design, encompassing 6020 embryos from 2879 PGT-A cycles conducted between February 2013 and September 2021. Trophectoderm biopsies in day 5 (D5) or day 6 (D6) blastocysts were analyzed by next generation sequencing (NGS). Only single embryo transfers (SET) were considered, totaling 1161 transfers. Of these, 49.9% resulted in positive pregnancy tests, with 18.3% experiencing BPL. To establish a predictive model for BPL, both classical statistical methods and five different supervised classification machine learning algorithms were used. A total of forty-seven factors were incorporated as predictor variables in the machine learning models.

RESULTS

Throughout the optimization process for each model, various performance metrics were computed. Random Forest model emerged as the best model, boasting the highest area under the ROC curve (AUC) value of 0.913, alongside an accuracy of 0.830, positive predictive value of 0.857, and negative predictive value of 0.807. For the selected model, SHAP (SHapley Additive exPlanations) values were determined for each of the variables to establish which had the best predictive ability. Notably, variables pertaining to embryo biopsy demonstrated the greatest predictive capacity, followed by factors associated with ovarian stimulation (COS), maternal age, and paternal age.

CONCLUSIONS

The Random Forest model had a higher predictive power for identifying BPL occurrences in PGT-A cycles. Specifically, variables associated with the embryo biopsy procedure (biopsy day, number of biopsied embryos, and number of biopsied cells) and ovarian stimulation (number of oocytes retrieved and duration of stimulation), exhibited the strongest predictive power.

Clinical outcomes of vitrified-warmed autologous oocyte cycles with 15-year follow-up at a single UK centre: consistent and predictable results

RESEARCH QUESTION

What were the clinical outcomes from 332 autologous vitrified- warmed oocyte cycles derived from 3182 elective autologous oocyte freeze cycles carried out between 2008 and 2022 in a single-centre series?

DESIGN

In this retrospective observational study, outcomes in 299 patients returning to use their frozen oocytes between 2015 and 2023 were analysed.

RESULTS

A total of 3328 elective oocyte vitrification cycles were performed in 2280 patients. The return rate to use oocytes was 14% (299/2171). Mean ages were 37.6 years at storage and 40 at warming. Ninety-three clinical pregnancies and 77 healthy live births were recorded. The live birth rate (LBR) was 24% (39/163) per fresh transfer and 17% (39/227) per embryo transferred. Stratified by age at freezing, the LBR per embryo transferred was 26% (12/47) in participants under 35 years, 20% (24/118) in those 35-39 years and 5% (3/62) in those 40+ years. Frozen embryo transfers (FET) achieved a 30% (24/80) LBR per embryo transfer and a 27% (24/90) LBR per embryo transferred. PGT-A for embryo selection doubled the LBR compared with FET from an untested embryo after one attempt (40% versus 21%). In patients aged over 40 years, the cumulative LBR reached 42% per patient in euploid FET.

CONCLUSION

The proportion of patients who returned to use their stored oocytes and the clinical outcomes were consistent with other recent reports and challenges the prevalent critical narrative regarding elective oocyte freezing for fertility preservation. The results are now comparable to routine IVF. Not everyone who returns to use their oocytes will conceive, but for those choosing to preserve their fertility, oocyte freezing can provide reproducible and reassuring results.

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.

Performance of preimplantation genetic testing for aneuploidy for patients with unexplained recurrent pregnancy loss and repeated implantation failure

Objective

The primary objective was to investigate whether the utilization of next-generation sequencing (NGS) for preimplantation genetic testing for aneuploidy (PGT-A) could enhance the reproductive outcomes in patients with unexplained recurrent pregnancy loss (uRPL) or unexplained repeated implantation failure (uRIF) undergoing intracytoplasmic sperm injection (ICSI) cycles.

Materials and methods

We studied the reproductive outcomes of uRPL or uRIF sufferers in Chengdu women and children's central hospital from July 2020 to Jan 2024 retrospectively. These patients were categorized into two groups based on whether they underwent PGT-A or not. As the patients in the PGT-A group all had ICSI and frozen-thawed embryo transfer (FET), only patients who underwent ICSI and FET were included in the non-PGT-A group for comparison. Demographic characteristics and reproductive outcomes were compared in uRPL or uRIF sufferers.

Results

For uRPL group, a significant increased ongoing pregnancy rate (63.6 % vs 26.1 %, p = 0.002) and reduced pregnancy loss rate (18.4 % vs 73.3 %, p < 0.001) were found in the PGT-A group in comparison with those in the non-PGT-A group. For uRIF group, no significant difference was noted in the HCG-positive rate, ongoing pregnancy rate, or pregnancy loss rate between the two groups. It is noteworthy that the maternal age in the PGT-A group was significantly higher than that in the non-PGT-A group (p = 0.048).

Conclusions

NGS-based PGT-A effectively optimized the reproductive outcomes in uRPL sufferers. Although its benefits in uRIF appeared to be limited, there is a potential advantage for those with advanced maternal age. Considering the small sample size, further randomized controlled trials are warranted to validate these findings.

MiR-135a-5p regulates window of implantation by suppressing pinopodes development and decidualization of endometrial stromal cells

PURPOSE

The window of implantation (WOI) is a brief period during which the endometrium is receptive to embryo implantation. This study investigated the relationship between miR-135a-5p and endometrial receptivity.

METHODS

Peripheral blood was collected on the day of ovulation and the 5th day after ovulation for high-throughput sequencing from women who achieved clinical pregnancy through natural cycle frozen embryo transfer. RT-qPCR assessed miR-135a-5p expression in the endometrium tissue or cells during the mouse implantation window or decidualization. Scanning electron microscopy was utilized to observe pinopode morphology and quantity in mice overexpressing miR-135a-5p during the WOI. Human endometrial stromal cells (HESC) and artificial induction of mouse uterine decidualization were used to explore whether miR-135a-5p overexpression inhibits decidualization by regulating HOXA10 and BMPR2. Furthermore, the impact of miR-135a-5p on HESC proliferation and HTR8/SVneo invasion was explored.

RESULTS

A total of 54 women were enrolled in the study. bioinformatics analysis and animal models demonstrated that miR-135a-5p was significantly downregulated during the WOI, and its high expression can lead to abnormal pregnancy outcomes. Overexpression of miR-135a-5p resulted in the absence of pinopode in mouse endometrial tissue during the WOI. High miR-135a-5p levels were found to potentially inhibit endometrial tissue decidualization by downregulating HOXA10 and BMPR2 expression. Finally, CEBPD was identified as a potential regulator of miR-135a-5p, which would explain the decreased miR-135a-5p expression during the WOI.

CONCLUSION

MiR-135a-5p expression is significantly downregulated during the WOI. High miR-135a-5p levels suppress pinopode development and endometrial tissue decidualization through HOXA10 and BMPR2, contributing to inadequate endometrial receptivity.

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.

Lessons learned from 64,071 embryos subjected to PGT for aneuploidies: results, recurrence pattern and indications analysis

RESEARCH QUESTION

What is the influence of biological, technical and clinical factors on embryo outcomes in preimplantation genetic testing for aneuploidies (PGT-A) and what is the recurrence pattern?

DESIGN

This retrospective study included 64,071 embryos undergoing PGT-A in the same laboratory between 2011 and 2019. Biopsies were performed at the day 3 embryo stage (48.32%) or blastocyst stage (51.70%). Advanced maternal age (AMA) was the main indication (65.62%).

RESULTS

The aneuploidy rate was 67.75%, higher in women aged over 35 years than in women aged 35 years or less (71.76% versus 47.44%), and higher in day 3 embryo versus blastocyst biopsies (77.51% versus 58.62%). The trisomy:monosomy ratio was 1.01 for blastocysts versus 0.84 for day 3 embryos. Trisomy 21 was present in 4.9% of embryos. In aneuploid embryos, the probability of having one or more involved chromosomes followed a decreasing exponential pattern. The probability of an embryo being euploid was constant at around 30% (40% in blastocysts, 20% in day 3 embryos). The cumulative probability of having one or more euploid embryos after 10 biopsied embryos was 94.79% in blastocysts and 80.61% in day 3 embryos. AMA was associated with a much higher aneuploidy rate than all other indications, which among them had similar aneuploidy rate and chromosomal involvement.

CONCLUSIONS

There is a considerably lower aneuploidy rate in blastocysts than day 3 embryos, which is most notable for monosomies. While AMA shows an increased aneuploidy rate and a specific chromosomal pattern of involvement, the remaining indications showed a similar aneuploidy rate and chromosomal pattern. Even after producing many consecutive aneuploid embryos, the possibility of obtaining a euploid embryo is not negligible.

The reproductive potential of vitrified-warmed euploid embryos declines following repeated uterine transfers

BACKGROUND

Recurrent implantation failure (RIF) represents a vague clinical condition with an unclear diagnostic challenge that lacks solid scientific underpinning. Although euploid embryos have demonstrated consistent implantation capabilities across various age groups, a unanimous agreement regarding the advantages of preimplantation genetic testing for aneuploidy (PGT-A) in managing RIF is absent. The ongoing discussion about whether chromosomal aneuploidy in embryos significantly contributes to recurrent implantation failure remains unsettled. Despite active discussions in recent times, a universally accepted characterization of recurrent implantation failure remains elusive. We aimed in this study to measure the reproductive performance of vitrified-warmed euploid embryos transferred to the uterus in successive cycles.

METHODS

This observational cohort study included women (n = 387) with an anatomically normal uterus who underwent oocyte retrieval for PGT-A treatment with at least one biopsied blastocyst, between January 2017 and December 2021 at a university-affiliated public fertility center. The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy and comprehensive 24-chromosome analysis of preimplantation embryos using Next Generation Sequencing (NGS). Women, who failed a vitrified-warmed euploid embryo transfer, had successive blastocyst transfer cycles (FET) for a total of three using remaining cryopreserved euploid blastocysts from the same oocyte retrieval cycle. The primary endpoints were sustained implantation rate (SIR) and live birth rate (LBR) per vitrified-warmed single euploid embryo. The secondary endpoints were mean euploidy rate (m-ER) per cohort of biopsied blastocysts from each patient, as well as pregnancy and miscarriage rates.

RESULTS

The mean age of the patient population was 33.4 years (95% CI 32.8-33.9). A total of 1,641 embryos derived from the first oocyte retrieval cycle were biopsied and screened. We found no associations between the m-ER and the number of previous failed IVF cycles among different ranges of maternal age at oocyte retrieval (P = 0.45). Pairwise comparisons showed a significant decrease in the sustained implantation rate (44.7% vs. 30%; P = 0.01) and the livebirth rate per single euploid blastocyst (37.1% vs. 25%; P = 0.02) between the 1st and 3rd FET. The cumulative SIR and LBR after up to three successive single embryo transfers were 77.1% and 68.8%, respectively. We found that the live birth rate of the first vitrified-warmed euploid blastocyst transferred decreased significantly with the increasing number of previously failed IVF attempts by categories (45.3% vs. 35.8% vs. 27.6%; P = 0.04). A comparable decrease in sustained implantation rate was also observed but did not reach statistical significance (50% vs. 44.2 vs. 37.9%; P = NS). Using a logistic regression model, we confirmed the presence of a negative association between the number of previous IVF failed attempts and the live birth rate per embryo transfer cycle (OR = 0.76; 95% CI 0.62-0.94; P = 0.01).

CONCLUSIONS

These findings are vital for enhancing patient counseling and refining management strategies for individuals facing recurrent implantation failure. By tailoring interventions based on age and ovarian reserve, healthcare professionals can offer more personalized guidance, potentially improving the overall success rates and patient experiences in fertility treatments.

TRIAL REGISTRATION NUMBER

N/A.

Preimplantation Genetic Testing for Aneuploidy Could Not Improve Cumulative Live Birth Rate Among 705 Couples with Unexplained Recurrent Implantation Failure

Objective

We evaluate whether next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) improves the cumulative pregnancy outcomes of patients with unexplained recurrent implantation failure (uRIF) as compared to conventional in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI).

Patients and Methods

This was a retrospective cohort study (2015-2022). A total of 705 couples diagnosed with uRIF were included in the study. 229 women transferred blastocysts based on morphological grading (IVF/ICSI) and 476 couples opted for PGT-A to screen blastocysts by NGS. Women were further stratified according to age at retrieval (<38 years and ≥38 years). The primary outcome was the cumulative live-birth rate after all the embryos were transferred in a single oocyte retrieval or until achieving a live birth. Confounders were adjusted using binary logistic regression models.

Results

Cumulative live-birth rate was similar between the IVF/ICSI group and the PGT-A group after stratified by age: IVF/ICSI vs PGT-A in the <38 years subgroup (49.7% vs 57.7%, adjusted OR (95% CI) = 1.25 (0.84-1.84), P = 0.270) and in the ≥38 years subgroup (14.0% vs 19.5%, adjusted OR (95% CI) = 1.09 (0.41-2.92), P = 0.866), respectively. Nonetheless, the PGT group had a lower first-time biochemical pregnancy loss rate (17.0% vs 8.7%, P = 0.034) and a higher cumulative good birth outcome rate (35.2% vs 46.4%, P = 0.014) than the IVF/ICSI group in the <38 years subgroup. Other pregnancy outcomes after the initial embryo transfer and multiple transfers following a single oocyte retrieval were all similar between groups.

Conclusion

Our results showed no evidence of favorable effects of PGT-A treatment on improving the cumulative live birth rate in uRIF couples regardless of maternal age. Use of PGT-A in the <38 years uRIF patients would help to decrease the first-time biochemical pregnancy loss and increase the cumulative good birth outcome.

Preimplantation genetic testing using comprehensive genomic copy number analysis is beneficial for balanced translocation carriers

Balanced chromosomal translocation is one of chromosomal variations. Carriers of balanced chromosomal translocations have an increased risk of spontaneous miscarriage. To avoid the risk, preimplantation genetic testing (PGT) using comprehensive genomic copy number analysis has been developed. This study aimed to verify whether and how embryos from couples in which one partner is a balanced translocation carrier have a higher ratio of chromosomal abnormalities. A total of 894 biopsied trophectoderms (TEs) were obtained from 130 couples in which one partner was a balanced translocation carrier (Robertsonian translocation, reciprocal translocation, or intrachromosomal inversion) and grouped as PGT-SR. Conversely, 3269 TEs from 697 couples who experienced recurrent implantation failure or recurrent pregnancy loss were included in the PGT-A group. The transferable blastocyst ratio was significantly lower in the PGT-SR group, even when bias related to the sample number and patient age was corrected. Subgroup analysis of the PGT-SR group revealed that the transferable blastocyst ratio was higher in the Robertsonian translocation group. Because the PGT-SR group had a higher proportion of untransferable embryos than the PGT-A group, PGT using comprehensive genomic copy number analysis was more beneficial for balanced translocation carriers than for infertility patients without chromosomal translocations. The frequencies of de novo aneuploidies were further analyzed, and the frequency in the PGT-SR group was lower than that in the PGT-A group. Therefore, we could not confirm the existence of interchromosomal effects in this study.

Role of immune cells in the establishment of implantation and maintenance of pregnancy and immunomodulatory therapies for patients with repeated implantation failure and recurrent pregnancy loss

Background

Immune cells play an important role in the establishment of pregnancy, and abnormalities in the immune system can cause implantation failure and miscarriage.

Methods

Previous papers have been summarized and the role of immune cells in reproduction is reviewed.

Results

The immune environment in the uterus changes drastically from before implantation to after pregnancy to maintain pregnancy. In allogeneic pregnancies, immature dendritic cells (DCs) that induce immune tolerance from outside the uterus flow into the uterus, and mature DCs that remain in the uterus express programmed cell death ligand 2, which suppresses the immune response. Macrophages are classified into M1-macrophages, which induce inflammation, and M2-macrophages, which suppress inflammation; M1-macrophages are required for luteinization, and M2-macrophages induce the differentiation of endometrial epithelial cells to enable implantation. Regulatory T cells, which suppress rejection, are essential for the implantation and maintenance of allogeneic pregnancies. Implantation failure and fetal loss are associated with decreased numbers or qualitative abnormalities of DCs, macrophages, and regulatory T cells. The clinical usefulness of immunomodulatory therapies in patients with repeated implantation failure and recurrent pregnancy loss has been reported.

Conclusion

The provision of individualized medical care in cases of implantation failure or miscarriage may improve clinical outcomes.

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.

Novel embryo selection strategies-finding the right balance

The use of novel technologies in the selection of embryos during in vitro fertilisation (IVF) has the potential to improve the chances of pregnancy and birth of a healthy child. However, it is important to be aware of the potential risks and unintended consequences that may arise from the premature implementation of these technologies. This article discusses the ethical considerations surrounding the use of novel embryo selection technologies in IVF, including the growing uptake of genetic testing and others, and argues that prioritising embryos for transfer using these technologies is acceptable, but discarding embryos based on unproven advances is not. Several historical examples are provided, which demonstrate possible harms, where the overall chance of pregnancy may have been reduced, and some patients may have missed out on biological parenthood altogether. We emphasise the need for caution and a balanced approach to ensure that the benefits of these technologies outweigh any potential harm. We also highlight the primacy of patients' autonomy in reproductive decision-making, especially when information gained by utilising novel technologies is imprecise.

Predicting risk of blastocyst aneuploidy among women with previous aneuploid pregnancy loss: a multicenter-data-based multivariable model

STUDY QUESTION

Can blastocyst aneuploidy be predicted for patients with previous aneuploid pregnancy loss (PAPL) and receiving preimplantation genetic testing for aneuploidy (PGT-A)?

SUMMARY ANSWER

Multivariable logistic regression models were established to predict high risk of blastocyst aneuploidy using four identified factors, presenting good predictive performance.

WHAT IS KNOWN ALREADY

Aneuploidy is the most common embryonic chromosomal abnormality leading to pregnancy loss. Several studies have demonstrated a higher embryo aneuploidy rate in patients with PAPL, which has suggested that PGT-A should have benefits in PAPL patients intending to improve their pregnancy outcomes. However, recent studies have failed to demonstrate the efficacy of PGT-A for PAPL patients. One possible way to improve the efficacy is to predict the risk of blastocyst aneuploidy risk in order to identify the specific PAPL population who may benefit from PGT-A.

STUDY DESIGN, SIZE, DURATION

We conducted a multicenter retrospective cohort study based on data analysis of 1119 patients receiving PGT-A in three reproductive medical centers of university affiliated teaching hospitals during January 2014 to June 2020. A cohort of 550 patients who had one to three PAPL(s) were included in the PAPL group. In addition, 569 patients with monogenic diseases without pregnancy loss were taken as the non-PAPL group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PGT-A was conducted using single nucleotide polymorphism microarrays and next-generation sequencing. Aneuploidy rates in Day 5 blastocysts of each patient were calculated and high-risk aneuploidy was defined as a rate of ≥50%. Candidate risk factors for high-risk aneuploidy were selected using the Akaike information criterion and were subsequently included in multivariable logistic regression models. Overall predictive accuracy was assessed using the confusion matrix, discrimination by area under the receiver operating characteristic curve (AUC), and calibration by plotting the predicted probabilities versus the observed probabilities. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

Blastocyst aneuploidy rates were 30 ± 25% and 21 ± 19% for PAPL and non-PAPL groups, respectively. Maternal age (odds ratio (OR) = 1.31, 95% CI 1.24-1.39, P < 0.001), number of PAPLs (OR = 1.40, 95% CI 1.05-1.86, P = 0.02), estradiol level on the ovulation trigger day (OR = 0.47, 95% CI 0.30-0.73, P < 0.001), and blastocyst formation rate (OR = 0.13, 95% CI 0.03-0.50, P = 0.003) were associated with high-risk of blastocyst aneuploidy. The predictive model based on the above four variables yielded AUCs of 0.80 using the training dataset and 0.83 using the test dataset, with average and maximal discrepancies of 2.89% and 12.76% for the training dataset, and 0.98% and 5.49% for the test dataset, respectively.

LIMITATIONS, REASONS FOR CAUTION

Our conclusions might not be compatible with those having fewer than four biopsied blastocysts and diminished ovarian reserves, since all of the included patients had four or more biopsied blastocysts and had exhibited good ovarian reserves.

WIDER IMPLICATIONS OF THE FINDINGS

The developed predictive model is critical for counseling PAPL patients before PGT-A by considering maternal age, number of PAPLs, estradiol levels on the ovulation trigger day, and the blastocyst formation rate. This prediction model achieves good risk stratification and so may be useful for identifying PAPL patients who may have higher risk of blastocyst aneuploidy and can therefore acquire better pregnancy outcomes by PGT-A.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China under Grant (81871159). No competing interest existed in the study.

TRIAL REGISTRATION NUMBER

N/A.

Economics of Fertility Care

Family building is a human right. The high cost and lack of insurance coverage associated with fertility treatments in the United States have made treatment inaccessible for many patients. The universal uptake of "add-on" services has further contributed to high out-of-pocket costs. Expansion in access to infertility care has occurred in several states through implementation of insurance mandates, and more employers are offering fertility benefits to attract and retain employees. An understanding of the economic issues shaping fertility should inform future policies aimed at promoting evidence-based practices and improving access to care in the United States.

Assessing the endometrium: An update on current and potential novel biomarkers of receptivity

A cyclical evolvement of the endometrium into a transient state of receptivity is crucial for acceptance of the semi-allogeneic foetus, conducive to pregnancy. Despite documentation of aberrances in this process within patients experiencing repeated embryo implantation failures and miscarriages, the endometrium is often overlooked in IVF clinics as the cause for failure. Focus instead is usually given to embryo-derived factors, such as aneuploidy. Nevertheless, failure of approximately 30 % of euploid embryos to implant demonstrates that other factors such as the endometrium require clinical exploration. Here, we review both traditional and novel methods used to assess endometrial receptivity such as identifying the WOI, endometrial immune profiling and transcriptomics panel testing. Where reported, we will also discuss their clinical application, as well as novel potential biomarkers within the pre-clinical research stages which show promise in their ability to assess endometrial receptivity.

Exploring the efficacy and beneficial population of preimplantation genetic testing for aneuploidy start from the oocyte retrieval cycle: a real-world study

BACKGROUND

Preimplantation genetic testing for aneuploidy (PGT-A) is widely used as an embryo selection technique in in vitro fertilization (IVF), but its effectiveness and potential beneficiary populations are unclear.

METHODS

This retrospective cohort study included patients who underwent their first oocyte retrieval cycles at CITIC-Xiangya between January 2016 and November 2019, and the associated fresh and thawed embryo transfer cycles up to November 30, 2020. PGT-A (PGT-A group) and intracytoplasmic sperm injection (ICSI)/IVF (non-PGT-A group) cycles were included. The numbers of oocytes and embryos obtained were unrestricted. In total, 60,580 patients were enrolled, and baseline data were matched between groups using 1:3 propensity score matching. Sensitivity analyses, including propensity score stratification and traditional multivariate logistic regression, were performed on the original unmatched cohort to check the robustness of the overall results. Analyses were stratified by age, body mass index, ovarian reserve/responsiveness, and potential indications to explore benefits in subgroups. The primary outcome was cumulative live birth rate (CLBR). The other outcomes included live birth rate (LBR), pregnancy loss rate, clinical pregnancy rate, pregnancy complications, low birth weight rate, and neonatal malformation rate.

RESULTS

In total, 4195 PGT-A users were matched with 10,140 non-PGT-A users. A significant reduction in CLBR was observed in women using PGT-A (27.5% vs. 31.1%; odds ratio (OR) = 0.84, 95% confidence interval (CI) 0.78-0.91; P < 0.001). However, women using PGT-A had higher first-transfer pregnancy (63.9% vs. 46.9%; OR = 2.01, 95% CI 1.81-2.23; P < 0.001) and LBR (52.6% vs. 34.2%, OR = 2.13, 95% CI 1.92-2.36; P < 0.001) rates and lower rates of early miscarriage (12.8% vs. 20.2%; OR = 0.58, 95% CI 0.48-0.70; P < 0.001), preterm birth (8.6% vs 17.3%; P < 0.001), and low birth weight (4.9% vs. 19.3%; P < 0.001). Moreover, subgroup analyses revealed that women aged ≥ 38 years, diagnosed with recurrent pregnancy loss or intrauterine adhesions benefited from PGT-A, with a significant increase in first-transfer LBR without a decrease in CLBR.

CONCLUSION

PGT-A does not increase and decrease CLBR per oocyte retrieval cycle; nonetheless, it is effective in infertile populations with specific indications. PGT-A reduces complications associated with multiple gestations.

Comparison of 1-year cumulative live birth and perinatal outcomes following single blastocyst transfer with or without preimplantation genetic testing for aneuploidy: a propensity score-matched study

PURPOSE

We evaluated whether preimplantation genetic testing for aneuploidy (PGT-A) could increase the cumulative live birth rate (CLBR) in patients with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL).

METHODS

The clinical records of 7,668 patients who underwent oocyte retrieval (OR) with or without PGT-A were reviewed for 365 days and retrospectively analyzed. Using propensity score matching, 579 patients in the PGT-A group were matched one-to-one with 7,089 patients in the non-PGT-A (control) group. Their pregnancy and perinatal outcomes and CLBRs were statistically compared.

RESULTS

The live birth rate per single vitrified-warmed blastocyst transfers (SVBTs) significantly improved in the PGT-A group in all age groups (P < 0.0002, all). Obstetric and perinatal outcomes were comparable between both groups regarding both RIF and RPL cases. Cox regression analysis demonstrated that in the RIF cases, the risk ratio per OR was significantly lower in the PGT-A group than in the control group (P = 0.0480), particularly in women aged < 40 years (P = 0.0364). However, the ratio was comparable between the groups in RPL cases. The risk ratio per treatment period was improved in the PGT-A group in both RIF and RPL cases only in women aged 40-42 years (P = 0.0234 and P = 0.0084, respectively).

CONCLUSION

Increased CLBR per treatment period was detected only in women aged 40-42 years in both RIF and RPL cases, suggesting that PGT-A is inappropriate to improve CLBR per treatment period in all RIF and RPL cases.

Update on preimplantation genetic testing for aneuploidy and outcomes of embryos with mosaic results

Preimplantation genetic testing for aneuploidy (PGT-A) is used as a frequent add-on for in-vitro fertilization (IVF) to improve clinical outcomes. The purpose is to select a euploid embryo following chromosomal testing on embryo biopsies. The current practice includes comprehensive chromosome screening (CCS) technology applied on trophectoderm (TE) biopsies. Despite its widespread use, PGT-A remains a controversial topic mainly because all of the RCTs comprised only good prognosis patients with 2 or more blastocysts available; hence the results are not generalizable to all groups of patients. Furthermore, with the introduction of the highly-sensitive platforms into clinical practice (i.e. next-generation sequencing [NGS]), a result consistent with intermediate copy number surfaced and is termed "Mosaic," consistent with a mixture of euploid and aneuploid cells within the biopsy sample. The optimal disposition and management of embryos with mosaic results is still an open question, as many 'mosaics' generated healthy live births with no identifiable congenital anomalies. The present article provides a complete and comprehensive up-to-date review on PGT-A. It discusses in detail the findings of all the published RCTs on PGT-A with CCS, comments on the subject of "mosaicism" and its current management, and describes the latest technique of non-invasive PGT-A.

Effects of NGS-based PGT-a for idiopathic recurrent pregnancy loss and implantation failure: a retrospective cohort study

To clarify the effect of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) combined with trophectoderm (TE) biopsy on the pregnancy outcomes of idiopathic recurrent pregnancy loss (iRPL) and idiopathic recurrent implantation failure (iRIF), we conducted a retrospective cohort study of 212 iRPL couples and 66 iRIF couples who underwent PGT-A or conventional in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. The implantation rate (IR) per transfer (64.2%), clinical pregnancy rate (CPR) per transfer (57.5%), and live birth rate (LBR) per transfer (45%) of iRPL couples of the PGT-A treatment group were significantly higher (p < 0.05) than those of the conventional IVF/ICSI group (IR per transfer,38.2%; CPR per transfer,33.3%; LBR per transfer, 28.4%), whereas the pregnancy loss rate (PLR) per transfer was similar between the two groups. These effects were also significant (p < 0.05) in iRPL couples with advanced maternal age (AMA, ≥35 years), whereas no significant differences were found in clinical outcomes between the PGT-A and conventional IVF/ICSI groups in younger iRPL couples (<35 years). The cumulative clinical outcomes of iRPL couples were comparable between the PGT-A and conventional IVF/ICSI groups. No significant differences were found in any clinical outcomes between the PGT-A and conventional IVF/ICSI groups for young or AMA couples with iRIF. In conclusion, NGS-based PGT-A involving TE biopsy may be useful for iRPL women to shorten the time to pregnancy and reduce their physical and psychological burden, especially for iRPL women with AMA; however, couples with iRIF may not benefit from PGT-A treatment. Considering the small sample size of the iRIF group, further investigations with a larger sample size are needed to verify our findings.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

Mitochondrial DNA mutations can influence the post-implantation development of human mosaic embryos

Introduction: Several healthy euploid births have been reported following the transfer of mosaic embryos, including both euploid and aneuploid blastomeres. This has been attributed to a reduced number of aneuploid cells, as previously reported in mice, but remains poorly explored in humans. We hypothesized that mitochondrial function, one of the most critical factors for embryonic development, can influence human post-implantation embryonic development, including a decrease of aneuploid cells in mosaic embryos. Methods: To clarify the role of mitochondrial function, we biopsied multiple parts of each human embryo and observed the remaining embryos under in vitro culture as a model of post-implantation development (n = 27 embryos). Karyotyping, whole mitochondrial DNA (mtDNA) sequencing, and mtDNA copy number assays were performed on all pre- and post-culture samples. Results: The ratio of euploid embryos was significantly enhanced during in vitro culture, whereas the ratio of mosaic embryos was significantly reduced. Furthermore, post-culture euploid and culturable embryos had significantly few mtDNA mutations, although mtDNA copy numbers did not differ. Discussion: Our results indicate that aneuploid cells decrease in human embryos post-implantation, and mtDNA mutations might induce low mitochondrial function and influence the development of post-implantation embryos with not only aneuploidy but also euploidy. Analyzing the whole mtDNA mutation number may be a novel method for selecting a better mosaic embryo for transfer.

Hyaluronan-enriched transfer medium (HETM) can improve the implantation rate in morphologically poor euploid blastocyst transfer

PURPOSE

Hyaluronan-enriched transfer medium (HETM) could improve the clinical pregnancy rate (CPR) for patients with repeated implantation failures (RIF). In contrast, there have been seldom reports addressing the potentially beneficial effects of HETM for morphologically poor blastocysts (MPBLs). Our study aimed to evaluate whether the use of HETM would improve the CPR for the patients who were transferred with euploid MPBLs.

METHODS

Patients who underwent single euploid blastocyst transfer between July 2020 and June 2022 were enrolled. We included only those blastocysts confirmed as euploid by PGT-A, and those blastocysts were transferred after thawing. The natural ovulatory cycle or hormone replacement cycle (HRC) protocol were used for endometrial preparation for frozen embryo transfer (FET). A total of 1,168 FET cycles were performed in the study period, including 954 cycles of morphologically good blastocysts (≥ 4BB in Gardner's classification), and 85 cycles of MPBLs, of which 47 were transferred using HETM in FET (the HETM group), and the remaining 38 were transferred with the medium without hyaluronan (the control group). We compared the CPR between these two groups.

RESULTS

The characteristics of patients were similar between the HETM and control groups. The CPR in the HETM group was significantly higher than the control group (47.4% and 21.5%, respectively, p = 0.019). The multiple logistic regression analysis found that the use of HETM was a predictive factor of positive pregnancy outcomes (OR = 5.08, 95% CI = 1.62-16.0, p = 0.019).

CONCLUSION

Our data suggests that HETM used in the euploid blastocyst transfer can improve the clinical pregnancy rates of morphologically poor blastocysts.

Preimplantation Genetic Testing for Aneuploidy for Recurrent Pregnancy Loss and Recurrent Implantation Failure in Minimal Ovarian Stimulation Cycle for Women Aged 35-42 Years: Live Birth Rate, Developmental Follow-up of Children, and Embryo Ranking

This study was aimed at exploring the benefits of preimplantation genetic testing for aneuploidy (PGT-A) in ensuring a successful pregnancy in patients with recurrent pregnancy loss (RPL) caused by an abnormal number of chromosomes in the embryo and recurrent implantation failure (RIF). Thirty-two patients who underwent PGT-A (18 in the RIF protocol and 14 in the RPL protocol) were enrolled in the study, and 2556 patients who did not undergo PGT-A during the same in vitro fertilization (IVF) treatment period were enrolled as controls. All patients underwent minimal stimulation cycle IVF. In the RPL protocol, the live birth rate per embryo transfer (ET) and that per patient were higher with PGT-A (80.0% each) than without it (0% each; P = 0.0050), and the rate of miscarriages was lower with PGT-A than without it (20.0% vs. 100.0%, P = 0.0098). In the RIF protocol, there were no significant differences in the live birth rate per ET and in the rate of miscarriages between groups with and without PGT-A-90.0% vs. 69.2% (P = 0.2313) and 0% vs. 10.0% (P = 0.3297), respectively. None of the children whose mothers underwent PGT-A presented adverse findings at a 1.5-year developmental check-up. In conclusion, PGT-A in RPL is advantageous for improving the live birth rate per ET and that per patient in minimal stimulation cycle IVF; it reduces the rate of miscarriages. In addition, PGT-A might be more beneficial for embryo selection than the existing morphological grades of blastocysts, resulting in earlier conception.

The age-related required number of zygotes estimated from prior clinical studies of preimplantation genetic testing for aneuploidy (PGT-A)

Women who are undergoing preimplantation genetic testing for aneuploidy (PGT-A) often wish to know how many eggs will be required to optimize the chances of a live birth. However, no precise data on this can yet be provided during genetic counseling for this procedure. On the basis of PGT-A data from related studies and current databases, we have estimated that the number of zygotes required for a 50% chance of a live birth is 8 at age 40 but increases markedly to 21 at age 43. PGT-A markedly reduces the miscarriage rate per embryo transfer but does not alleviate the extremely high number of zygotes required for a live birth in women of an advanced maternal age. Detailed genetic counseling will therefore be desirable prior to undergoing this procedure.

Does embryo categorization by existing artificial intelligence, morphokinetic or morphological embryo selection models correlate with blastocyst euploidy rates?

RESEARCH QUESTION

Does embryo categorization by existing artificial intelligence (AI), morphokinetic or morphological embryo selection models correlate with blastocyst euploidy?

DESIGN

A total of 834 patients (mean maternal age 40.5 ± 3.4 years) who underwent preimplantation genetic testing for aneuploidies (PGT-A) on a total of 3573 tested blastocysts were included in this retrospective study. The cycles were stratified into five maternal age groups according to the Society for Assisted Reproductive Technology age groups (<35, 35-37, 38-40, 41-42 and >42 years). The main outcome of this study was the correlation of euploidy rates in stratified maternal age groups and an automated AI model (iDAScore® v1.0), a morphokinetic embryo selection model (KIDScore Day 5 ver 3, KS-D5) and a traditional morphological grading model (Gardner criteria), respectively.

RESULTS

Euploidy rates were significantly correlated with iDAScore (P = 0.0035 to <0.001) in all age groups, and expect for the youngest age group, with KS-D5 and Gardner criteria (all P < 0.0001). Additionally, multivariate logistic regression analysis showed that for all models, higher scores were significantly correlated with euploidy (all P < 0.0001).

CONCLUSION

These results show that existing blastocyst scoring models correlate with ploidy status. However, as these models were developed to indicate implantation potential, they cannot accurately diagnose if an embryo is euploid or aneuploid. Instead, they may be used to support the decision of how many and which blastocysts to biopsy, thus potentially reducing patient costs.

Immune alterations in recurrent implantation failure

A failure to achieve pregnancy after three or more embryo transfer cycles with high-quality blastocysts is referred to as recurrent implantation failure (RIF). RIF can be due to altered uterine factors or male factors or embryo factors. Disrupted endometrial receptivity, altered expression of genes in several pathways, immunologic disturbances in the peripheral blood and/or the endometrium, and epigenetic alterations are associated with RIF. Amongst the immunologic disturbances, altered Th1/Th2 ratio, altered NK cell and macrophage numbers are observed in women with RIF. However, not all women with RIF have the same kind of immune dysfunction suggesting that RIF is a heterogeneous condition associated with varied immune responses and one size may not fit all. Thus, personalized therapies based on the immune status of the patient are being tested in women with RIF. In general, women with a high Th1/Th2 ratio are offered Tacrolimus, while intravenous IgG is recommended in women with high NK cell numbers/HLA mismatch. Women with hyperactivated immune status in the uterus are offered progesterone support, prednisolone, vitamin E, and intralipid treatment to suppress inflammation and oxidative stress, while endometrial scratching and intrauterine hCG administration are offered to women with hypo-active immune status. There is a need for standardized tests for evaluation of immune status in patients and sufficiently powered randomized controlled trials for personalized therapies to determine which of these will be beneficial in women with RIF. Till then, the ART community should limit the use of such add-on interventions in women with RIF.

Impact of recurrent pregnancy loss history on reproductive outcomes in women undergoing fertility treatment

BACKGROUND

Recurrent pregnancy loss negatively affects the reproductive outcomes of natural conception. Preimplantation genetic testing for aneuploidies has been the focus of interventions in women with recurrent pregnancy loss. However, the risk of no embryos being available, high costs, and uncertainties surrounding its effectiveness limit its use. Factors beyond euploidy, such as an appropriate intrauterine environment, are also important for improving the reproductive outcomes in women with recurrent pregnancy loss. It remains unknown whether a history of recurrent pregnancy loss can affect reproductive outcomes after fertility treatment.

OBJECTIVE

This study aimed to investigate the impact of history of recurrent pregnancy loss on the reproductive outcomes of women undergoing fertility treatment.

STUDY DESIGN

This was a retrospective cohort study of women who underwent their first frozen embryo transfer cycle or intrauterine insemination cycle between January 2014 and July 2020 in Shanghai, China. We excluded couples with known karyotypic abnormalities (eg, balanced translocation) or uterine malformation. We performed multivariate binary logistic regressions for biochemical pregnancy, miscarriage, and live birth rates to investigate the associations between recurrent pregnancy loss history and reproductive outcomes.

RESULTS

A total of 29,825 women who underwent frozen embryo transfer cycles and 5476 women who underwent intrauterine insemination cycles were included in this study. In those who underwent frozen embryo transfer, history of recurrent pregnancy loss was not significantly associated with biochemical pregnancy (adjusted odds ratio, 1.19; 95% confidence interval, 0.87-1.63), miscarriage (adjusted odds ratio, 0.99; 95% confidence interval, 0.78-1.26), or live birth rates (adjusted odds ratio, 0.91; 95% confidence interval, 0.79-1.06). Similarly, in frozen embryo transfer cycles that led to clinical pregnancy, recurrent pregnancy loss history was not significantly associated with live birth (adjusted odds ratio, 0.99; 95% confidence interval, 0.76-1.28) or miscarriage rates (adjusted odds ratio, 1.04; 95% confidence interval, 0.81-1.35). In women with intrauterine insemination, history of recurrent pregnancy loss showed no significant associations with fertility outcomes in all cycles ([adjusted odds ratio, 1.36; 95% confidence interval, 0.88-2.10] for live birth rate and [adjusted odds ratio, 1.74; 95% confidence interval, 0.75-4.01], for miscarriage rate) and in cycles that led to clinical pregnancy ([adjusted odds ratio, 0.70; 95% confidence interval, 0.31-1.63] for live birth rate and [adjusted odds ratio, 1.45; 95% confidence interval, 0.58-3.63] for miscarriage rate).

CONCLUSION

In women without obvious chromosome abnormality and uterine malformation who undergo fertility treatment, recurrent pregnancy loss history was not significantly associated with miscarriage and live birth rates, suggesting that it has little or no prognostic value in predicting the reproductive outcomes of frozen embryo transfer or intrauterine insemination cycles.

Is it necessary for young patients with recurrent implantation failure to undergo preimplantation genetic testing for aneuploidy?

OBJECTIVE

To determine whether preimplantation genetic testing for aneuploidy (PGT-A) can improve the pregnancy outcomes of patients aged under 38 years who have a history of recurrent implantation failure(RIF).

DESIGN

Retrospective cohort study.

METHODS

We retrospectively studied the pregnancy outcomes of RIF patients aged under 38 years from January 2017 to December 2021.178 patients were divided into two groups according to whether they underwent PGT-A: the PGT-A group(n=59)and the control group(n=119).In the PGT-A group, we compared the euploidy rate of the different quality and developmental rate blastocysts. In both groups,the patients were the first frozen-thaw single blastocysts transfer after the diagnosis of RIF. Among the pregnancy outcomes, the clinical pregnancy rate was assessed as the primary outcome. The spontaneous abortion rate and ongoing pregnancy rate were the secondry outcomes. The generalized estimation equation was used to adjust for the blastocysts derived from the same patients. Multivariate logistic analysis models were used to compare the pregnancy outcomes between the two groups.

RESULTS

In the PGT-A group, 293 blastocysts obtained from59 patients underwent PGT-A. The proportions of euploidy, aneuploidy and mosaic blastocysts were 56.31%, 25.60% and 18.09%, respectively. A comparison of the euploidy rates of different quality blastocysts showed that the rate of good-quality blastocysts was significantly higher than that of poor-quality blastocysts (67.66% vs 46.88%; odds ratio [OR], 2.203; 95%confidence interval[CI], 0.943-3.612; P=0.002). However, no significant difference was observed in the different developmental rates blastocysts. Compared with Day 5 blastocysts, the euploidy rates of Day 6 and Day 7 blastocysts were not significantly different(61.54%vs51.91%; OR,0.945; 95%CI, 0.445-2.010; P=0.884; and 61.54%vs47.37%; OR, 1.106; 95%CI, 0.774-1.578; P=0.581, respectively).As for the pregnancy outcomes, the clinical pregnancy rate was significantly increase after the use of PGT-A compared with the control group(71.19%vs56.30%; OR, 0.538; 95%CI, 0.262-1.104; P=0.039). However, the spontaneous abortion rates and ongoing pregnancy rates were not significantly different between the control and PGT-A groups (21.43% vs 19.40%; aOR,0.727; 95%CI,0.271-1.945; P=0.525; and55.93% vs 45.38%; aOR, 0.649; 95%CI, 0.329-1.283; P = 0.214,respectively).

CONCLUSION

PGT-A improved the clinical pregnancy rate after blastocyst transfer in RIF patients aged under 38 years.

Growth hormone supplementation ameliorates blastocyst euploidy rates and improves pregnancy outcomes in women undergoing preimplantation genetic testing for aneuploidy cycles

BACKGROUND

Growth hormone (GH) supplementation has been shown to improve oocyte quality and live birth, but few studies have examined whether GH can reduce embryonic aneuploidy. Chromosomal abnormalities in preimplantation embryos have been regarded as the principal cause of implantation failure and miscarriage, and an increased percentage of aneuploid embryos has been observed in patient cohorts with unexplained recurrent pregnancy loss (RPL), recurrent implantation failure (RIF), and advanced maternal age.

METHODS

This prospective cohort study was conducted on women whose previous PGT-A cycle ended up with no transferrable blastocysts, or the aneuploidy rate was above 50% and no live birth was acquired. The participants were divided into GH co-treatment and comparison groups according to whether GH was administered in the subsequent PGT-A cycle. In addition, within the GH co-treatment group, the previous failed cycle constituted the self-control group.

RESULTS

208 women were recruited in the study (GH co-treatment group: 96 women, comparison group: 112 women). Compared to the self-control and comparison groups, the rate of euploid blastocysts was significantly higher in the GH co-treatment group (GH vs self-control: 32.00% vs 9.14%, odds ratio [OR]: 4.765, 95% confidence interval [CI]: 2.420-9.385, P < 0.01; GH vs comparison: 32.00% vs. 21.05%, OR: 1.930, 95% CI: 1.106-3.366, P = 0.021), and their frozen embryo transfers resulted in more pregnancies and live births. In the subgroup analysis, for the <35 and 35-40 years groups, the euploidy rate in the GH co-treatment group was significantly higher than those in the self-control and comparison groups, but in the >40 years group, there was no difference in euploidy rate.

CONCLUSION

Our study presents preliminary evidence that GH supplementation may ameliorate blastocyst aneuploidy and improve pregnancy outcomes in women who have previously experienced pregnancy failures along with high aneuploidy rates, particularly in those younger than 40 years. Therefore, the use of GH in such women should be considered. However, considering the limited sample size and mixed indications for PGT-A, further scientific research on the underlying mechanism as well as clinical trials with larger sample sizes are needed to confirm the effects and optimal protocols.

Preimplantation genetic testing for aneuploidy: helpful but not a first choice

PURPOSE

This retrospective cohort study aimed to assess and compare the outcomes between cumulative live birth of patients with and without PGT-A and also between prior unsuccessful IVF cycles and PGT-A cycles among patients who experienced IVF but without live birth delivery, and to clarify the effective usage of PGT-A as an in vitro fertilization (IVF) add-on.

METHODS

A total of 2113 females undergoing IVF with at least one blastocyst were reviewed. Patients in the PGT-A and non-PGT-A groups were further categorized into first-time IVF and prior unsuccessful IVF groups (previous IVF experience but without live birth delivery).

RESULTS

In the PGT-A group, there were additional oocyte retrieval cycles, fewer transfer cycles per patient, higher clinical pregnancy rates per embryo transfer, and lower miscarriage rates per clinical pregnancy as compared to the non-PGT-A group, all showing significant differences. However, the first-time IVF group with PGT-A had a significantly longer duration from the first oocyte retrieval to the first live birth delivery (LBD) and a significantly lower LBD rate per patient than the non-PGT-A group. The cumulative probability for a first LBD with PGT-A was inferior in the first-time IVF group for women < 35 years, marginally superior in the prior unsuccessful IVF group of women aged 38-40 years, and similar for other groups.

CONCLUSION

PGT-A should not be recommended to all patients; however, if the first IVF treatment failed, PGT-A may reduce the patient's burden regardless of age.

Transcriptomic signatures in trophectoderm and inner cell mass of human blastocysts classified according to developmental potential, maternal age and morphology

Selection of high-quality embryos is important to achieve successful pregnancy in assisted reproductive technology (ART). Recently, it has been debated whether RNA-sequencing (RNA-Seq) should be applied to ART to predict embryo quality. However, information on genes that can serve as markers for pregnant expectancy is limited. Furthermore, there is no information on which transcriptome of trophectoderm (TE) or inner cell mass (ICM) is more highly correlated with pregnant expectancy. Here, we performed RNA-Seq analysis of TE and ICM of human blastocysts, the pregnancy expectation of which was retrospectively determined using the clinical outcomes of 1,890 cases of frozen-thawed blastocyst transfer. We identified genes that were correlated with the expected pregnancy rate in ICM and TE, respectively, with a larger number of genes identified in TE than in ICM. Downregulated genes in the TE of blastocysts that were estimated to have lower expectation of pregnancy included tight junction-related genes such as CXADR and ATP1B1, which have been implicated in peri-implantation development. Moreover, we identified dozens of differentially expressed genes by regrouping the blastocysts based on the maternal age and the Gardner score. Additionally, we showed that aneuploidy estimation using RNA-Seq datasets does not correlate with pregnancy expectation. Thus, our study provides an expanded list of candidate genes for the prediction of pregnancy in human blastocyst embryos.

Patients with Recurrent Pregnancy Loss Have Similar Embryonic Preimplantation Genetic Testing Aneuploidy Rates and In Vitro Fertilization Outcomes to Infertility Patients

Objective

To evaluate aneuploidy rates and in vitro fertilization (IVF)/pregnancy outcomes for patients undergoing IVF and preimplantation genetic testing for aneuploidy (PGT-A) with a recurrent pregnancy loss (RPL) diagnosis compared to infertility diagnoses without RPL.

Design

Retrospective cohort study.

Setting

Academic fertility center.

Patients

Of 372 patients undergoing IVF/PGT-A between January 2016-December 2018, 294 patients were included in the analysis: 56 patients with an RPL diagnosis and 238 with infertility diagnoses without RPL.

Interventions

None.

Main Outcome Measures

The primary outcome measured was the embryonic aneuploidy rate. Secondary outcomes included fertilization and blastulation rates, number of blastocysts biopsied, cycles without euploid blastocysts, and rates of pregnancy losses, clinical pregnancies, and live births after a euploid embryo transfer.

Results

The cohort included 56 patients with RPL and 238 patients without RPL, including data from their first IVF cycle within the time period. Aneuploidy rates were similar between the groups, with a mean of 55% (±31%) in RPL and 54% (±34%) in non-RPL cycles. Similar rates persisted after controlling for age, ovarian reserve, and infertility diagnosis. Fertilization and blastulation rates, as well as cumulative clinical pregnancy, pregnancy loss, and live birth rates after the transfer of at least one euploid embryo were also similar between the two groups.

Conclusions

These results suggest that IVF/PGT-A cycles from patients with an RPL diagnosis have similar IVF and pregnancy outcomes to those of patients with infertility without RPL. This research can help guide counseling for RPL patients considering IVF with PGT-A.

Prevention of intrauterine fetal growth restriction by administrating C1q/TNF-related protein 6, a specific inhibitor of the alternative complement pathway

PURPOSE

The latest treatments do not sufficiently prevent miscarriage and fetal growth restriction (FGR) in pregnant women. Here, we assessed the effects of a human protein, CTRP6, that specifically inhibits the activation of the alternative complement pathway on miscarriage, fetal and placental development.

METHODS

Pregnant CBA/J mice mated with DBA/2 male mice as a model of spontaneous abortion and FGR were randomly divided into the control and CTRP6 groups. In the CTRP6 group, the mice were intravenously administered CTRP6 on days 4.5 and 6.5 post-conception (dpc). The abortion rate and fetal and placental weights on 14.5 dpc were examined. Remodeling of the spiral artery was also assessed.

RESULTS

The abortion rate in the CTRP6 group (13%) was reduced compared to the control group (21%), but there was no statistical difference. The placental and fetal weights in the CTRP6 group were also heavier than those in the control (P < 0.05). Moreover, the thickness of the blood vessel wall in the CTRP6 group was significantly thinner than that in the control (P < 0.05) and comparable to that in the non-abortion model (CBA/J x BALB). The ratio of the inner-per-the-outer diameter of the spiral artery increased more in the CTRP6 group than that in the control (P < 0.05). As well, the Th1/Th2 cytokine ratio was significantly reduced by CTRP6 treatment.

CONCLUSIONS

Taken together, the supplementation with a protein that regulates the alternative complement pathway in vivo improves FGR and promotes spiral artery remodeling in a mouse model of miscarriage and FGR.

Implementation and Evaluation of Preimplantation Genetic Testing at Vilnius University Hospital Santaros Klinikos

Background and Objectives

The most effective treatment of infertility is in vitro fertilization (IVF). IVF with Preimplantation Genetic Testing (PGT) allows to identify embryos with a genetic abnormality associated with a specific medical disorder and to select the most optimal embryos for the transfer. PGT is divided into structural rearrangement testing (PGT-SR), monogenetic disorder testing (PGT-M), and aneuploidy testing (PGT-A). This study mostly analyzes PGT-SR, also describes a few cases of PGT-M. The aim of this study was to implement PGT procedure at Vilnius University Hospital Santaros Klinikos (VUHSK) Santaros Fertility Centre (SFC) and to perform retrospective analysis of PGT procedures after the implementation.

Materials and Methods

A single-center retrospective analysis was carried out. The study population included infertile couples who underwent PGT at SFC, VUHSK from January 01st, 2017 to December 31st, 2020. Ion PGM platform (Life Technologies, USA) and Ion ReproSeq PGS View Kit (Life Technologies, USA) were used for the whole genome amplification. Results were assessed using descriptive statistics.

Results

PGT was successfully implemented in VUHSK in 2017. During the analyzed time period, thirty-four PGT procedures were performed for 26 couples. Two procedures were performed in 2017, 7 procedures - in 2018, 13 - in 2019, and 12 - in 2020. In comparison with all IVF procedures, 2.5% procedures were IVF with PGT, a highest percentage was in 2020 (3.8% of all procedures). The main indication for PGT was balanced chromosomal rearrangements (in 85.3% cases). In all 34 cases 515 oocytes were aspirated in total, 309 oocytes were fertilized, oocytes fertilization rate exceeded 60%. A normal diploid karyotype was found in 46 (16.8%) biopsied embryos. Out of all PGT procedures, 9 (26.5%) resulted in a clinical pregnancy. Six (66.7%) pregnancies were confirmed in 2019, and 3 (33.3%) - in 2020. Three (33.3%) pregnancies resulted in spontaneous abortion, 6 (66.7%) - in delivery.

Conclusions

The implementation of PGT in VUHSK was successful. The most common indication for PGT was a reciprocal translocation. Oocytes fertilization rate exceeded 60%, a normal karyotype was found less than in one-fifth of biopsied embryos. A highest clinical pregnancy rate was achieved in 2019 when almost half of women conceived, which is probably related to the experience gained by the multidisciplinary team. This is the first study analyzing IVF with PGT in Lithuania, however, the results should be interpreted with caution due to a low number of total procedures performed.

Noninvasive Chromosome Screening for Evaluating the Clinical Outcomes of Patients With Recurrent Pregnancy Loss or Repeated Implantation Failure

This retrospective cohort study explores whether noninvasive chromosome screening (NICS) for aneuploidy can improve the clinical outcomes of patients with recurrent pregnancy loss (RPL) or repeated implantation failure (RIF) in assisted reproductive technology. A total of 273 women with a history of RPL or RIF between 2018 and 2021 were included in this study. We collected data of all oocyte retrieval cycles and single blastocyst resuscitation transfer cycles. For the patients experiencing RPL, NICS reduced the miscarriages rate per frozen embryo transfer (FET), improved the ongoing pregnancies rate and live birth rate: 17.9% vs 42.6%, adjusted OR 0.39, 95% CI 0.16-0.95; 40.7% vs 25.0%, adjusted OR 2.00, 95% CI 1.04-3.82; 38.9% vs 20.6%, adjusted OR 2.53, 95% CI 1.28-5.02, respectively. For the patients experiencing RIF, the pregnancy rates per FET in the NICS group were significantly higher than those in the non-NICS group (46.9% vs. 28.7%, adjusted OR 2.82, 95% CI 1.20-6.66). This study demonstrated that the selection of euploid embryos through NICS can reduce the miscarriage rate of patients experiencing RPL and improve the clinical pregnancy rate of patients experiencing RIF. Our data suggested NICS could be considered as a possibly useful screening test in clinical practice.

Search for morphological indicators that predict implantation by principal component analysis using images of blastocyst

Background

Although the current evaluation of human blastocysts is based on the Gardner criteria, there may be other notable parameters. The purpose of our study was to clarify whether the morphology of blastocysts has notable indicators other than the Gardner criteria.

Methods

To find such indicators, we compared blastocysts that showed elevated human chorionic gonadotropin (hCG) levels after transplantation (hCG-positive group; n = 129) and those that did not (hCG-negative group; n = 105) using principal component analysis of pixel brightness of the images.

Results

The comparison revealed that the hCG-positive group had grainy morphology and the hCG-negative group had non-grainy morphology. Classification of the blastocysts by this indicator did not make a difference in Gardner score. Interestingly, all embryos with ≥20% fragmentation were non-grainy. The visual classification based on this analysis was significantly more accurate than the prediction of implantation using the Gardner score ≥3BB. As graininess can be used in combination with the Gardner score, this indicator will enhance current reproductive technologies.

The effects of differences in trophectoderm biopsy techniques and the number of cells collected for biopsy on next‐generation sequencing results

Purpose

To examine how differences in trophectoderm biopsy techniques affect the frequency of mosaic embryos and sequencing results.

Methods

We examined differences in next‐generation sequencing (NGS) analysis results among operators or according to biopsy technique. Additionally, we determined the cut‐off for the number of collected cells to predict the occurrence of mosaicism. We collected cells according to the cut‐off value and examined whether there was a difference in the NGS analysis results between the pulling and flicking methods.

Results

There was no difference in the NGS analysis results among the operators. Regarding re‐biopsy, changes in the mosaic were observed in all specimens. The cut‐off value for the number of collected cells was five, and when more than five cells were collected, there was no difference in the NGS analysis results between the two methods.

Conclusions

We demonstrated that if trophectoderm biopsy techniques and NGS are stable, the cell collection location has a greater effect on NGS results than the biopsy technique.

Improved pregnancy outcomes of cyclosporine A on patients with unexplained repeated implantation failure in IVF/ICSI cycles: A retrospective cohort study

PROBLEM

Repeated implantation failure (RIF) is a daunting obstacle restricting the further improvement of embryo implantation rate (IR) and live birth rate (LBR). The beneficial effect of cyclosporine A (CsA) on reproductive outcomes of unexplained RIF(URIF) was explored after de novo embryo transfer (ET).

METHOD OF STUDY

A retrospective cohort study was conducted, comparing pregnancy outcomes of 146 cycles (CsA group, n = 62; control group, n = 84) at the IVF center of Suzhou Municipal Hospital from April 2016 to March 2020.

RESULTS

Baseline and transfer cycle characteristics of participants were comparable between groups. Overall, CsA exerted obvious improvement on IR (51.16% vs 31.97%, P = .006), clinical pregnancy rate (CPR) (58.06% vs 38.10%, P = .017), and LBR (48.39% vs 32.14%, P = .047). Especially, CsA showed remarkably enhancement on IR (41.38% vs 14.63%, P = .012), CPR (47.62% vs 17.24%, P = .021) of non-high quality embryos. No difference in obstetric and pediatric complications was observed, and no birth defects were reported under CsA application. CsA was found to be a predictor of clinical pregnancy [fine adjusted OR 2.360, 95 % CI 1.165-4.781; P = .017] and live birth [fine adjusted OR 2.339, 95% CI 1.124-4.867; P = .023] for multivariate logistic regression. Not surprisingly, the number of high quality embryos should also be considered as an independent predictor for clinical pregnancy [fine adjusted OR 1.637,95%CI 1.027-2.609; P = .038] and live birth [fine adjusted OR 1.890, 95% CI 1.165-3.068; P = .010].

CONCLUSION

CsA application in patients with URIF promotes the pregnancy outcomes and does not increase the risk of obstetric and pediatric complications.

Selecting Euploid Embryos for Transfer by Preimplantation Genetic Testing with the Help of Next-Generation Sequencing in Poor Prognosis Patients: A Retrospective Cohort Analysis

Background

The current embryo selection methods rely on subjective grading of embryo morphology or a real-time monitoring of the embryonic development and assessment of multiple quantitative endpoints. Even up to 40% of morphologically normal embryos harbour aneuploidies. Preimplantation genetic testing (PGT) is a technology, which gives opportunity to identify euploid embryos before implantation.

Aims

This study seeks to determine the role of PGT in poor prognosis patients, i.e., patients with advanced maternal age (AMA) (maternal age ≥35 years), recurrent pregnancy loss (RPL) (miscarriages ≥2) and recurrent implantation failures (RIFs) (in vitro fertilisation failures ≥3).

Study Setting and Design

A retrospective case-control study was done on a group of patients who underwent intracytoplasmic sperm injection for the indications of AMA, RPL and RIF.

Materials and Methods

In 33 cases who opted for PGT, day 5 blastocysts were subjected to trophectoderm biopsy with the help of next-generation sequencing. Euploid blastocyst was transferred in hormone replacement cycle at a later date. In 154 controls, blastocyst transfer was done based on morphological grading. Pregnancy outcomes are compared in terms of implantation rate, pregnancy rate, miscarriage rate and multiple pregnancy rate.

Statistical Analysis

Chi-square test was used for comparisons between the study groups with respect to percentage. P < 0.05 was considered statistically significant.

Results

The highest aneuploidy rate was found in embryos with AMA. Implantation rate was found to be statistically significantly higher in the PGT group as compared to the non-PGT group. However, take-home baby rates were not improved by PGT. There were less number of mean embryos transferred in the PGT group and lower multiple pregnancy rate.

Conclusions

With the application of PGT, embryo selection rates and implantation rates improved in poor prognosis patients.

The impact of preimplantation genetic testing for aneuploidies (PGT-A) on clinical outcomes in high risk patients

PURPOSE

To investigate whether preimplantation genetic testing for aneuploidy (PGT-A) improves the clinical outcome in patients with advanced maternal age (AMA), recurrent miscarriages (RM), and recurrent implantation failure (RIF).

METHODS

Retrospective cohort study from a single IVF center and a single genetics laboratory. One hundred seventy-six patients undergoing PGT-A were assigned to three groups: an AMA group, an RM group, and a RIF group. Two hundred seventy-nine patients that did not undergo PGT-A were used as controls and subgrouped similarly to the PGT-A cohort. For the PGT-A groups, trophectoderm biopsy was performed and array comparative genomic hybridization was used for PGT-A. Clinical outcomes were compared with the control groups.

RESULTS

In the RM group, we observed a significant decrease of early pregnancy loss rates in the PGT-A group (18.1% vs 75%) and a significant increase in live birth rate per transfer (50% vs 12.5%) and live birth rate per patient (36% vs 12.5%). In the RIF group, a statistically significant increase in the implantation rate per transfer (69.5% vs 33.3%) as well as the live birth rate per embryo transfer (47.8% vs 19%) was observed. In the AMA group, a statistically significant reduction in biochemical pregnancy loss was observed (3.7% vs 31.5%); however, live birth rates per embryo transfer and per patient were not significantly higher than the control group.

CONCLUSION

Our results agree with recently published studies, which suggest caution in the universal application of PGT-A in women with infertility. Instead, a more personalized approach by choosing the right candidates for PGT-A intervention should be followed.

Impact of mode of conception on early pregnancy human chorionic gonadotropin rise and birth weight

Objective

To assess whether the mode of conception and embryo biopsy impact first-trimester human chorionic gonadotropin (hCG) dynamics and subsequent risk of small for gestational age (SGA) or large for gestational age (LGA).

Design

Retrospective cohort study.

Setting

University fertility center.

Patients

Six hundred-two pregnant patients with singleton live births.

Interventions

Serial serum hCG measurements were obtained between 10 and 28 days postconception to determine the within-woman rate of change in hCG (slope) by mode of conception (unassisted pregnancy, fresh embryo transfer (ET), frozen ET, and frozen ET following preimplantation genetic testing for aneuploidy (PGT-A).

Main Outcome Measures

Primary outcomes included birth weight, SGA, and LGA.

Results

Mode of conception is not independently associated with birth weight, SGA, or LGA. Mediation analysis revealed an expected one-day increase in log-transformed hCG varied by mode of conception: unassisted (0.41), fresh ET (0.39), frozen ET (0.42), PGT-A (0.44). Human chorionic gonadotropin rise has a positive effect on birth weight (55 g per SD increase in hCG slope) and is associated with SGA (odds ratio, 0.65), but not with LGA (odds ratio, 1.18).

Conclusions

Human chorionic gonadotropin rise is an important mediator of the mode of conception/birth weight relationship. Preimplantation genetic testing for aneuploidy has the highest rate of hCG rise, followed by frozen ET, unassisted, and fresh ET. Faster rise is associated with higher birth weight and lower risk of SGA but does not impact LGA risk. Importantly, PGT-A does not increase the risk of extreme birth weight relative to other modes of conception evaluated.

Disrupting the biological clock: Fertility benefits, egg freezing and proactive fertility management

In the last decade, the in-vitro fertilization (IVF) sector has witnessed a shift from so-called 'reactive IVF' to a new model of proactive fertility care. Whereas IVF was traditionally developed to treat people who found they were unable to conceive, the indication for IVF has broadened significantly to include a much wider group of potential patients through a new focus on proactive treatment of future (in)fertilities. This shift combines a number of new trends pertaining to preservation, prediction, private equity and platformization, all of which have gained influence in contemporary assisted reproduction. This article focuses on the emergence of company-sponsored fertility benefits, which combines each of these trends. Whereas fertility benefits - especially egg freezing insurance - have primarily been discussed in terms of women's empowerment or disenfranchisement, this article instead calls attention to the discursive, clinical and infrastructural shifts in contemporary assisted reproduction that have emerged with the rising popularity of these benefits. The analysis addresses these underdiscussed aspects of fertility benefits by focusing on the dynamics of demand; the shifts in the rationalization of intensified treatment pathways in the face of new reimbursement practices; and the online, platform-based infrastructures that are built to provide these treatments. In doing so, it analyses how this remaking of fertility towards an ethos of proactive fertility management reflects broader capitalist tailwinds.

Case Report: Twin Pregnancy Gives Birth to a Girl with Partial Trisomy 21 Mosaicism after in vitro Fertilization and Embryo Transfer

Objective: To report a rare case in which an IVF-ET twin pregnancy gave birth to a partial trisomy 21 chimera girl.

Design: Case report.

Setting: University hospital.

Patient: A girl with partial trisomy 21 mosaicism after in vitro fertilization and embryo transfer.

Interventions:In vitro fertilization (IVF) and embryo transfer (ET).

Main Outcome Measure: Karyotype analysis, Copy Number Variation sequencing (CNV-seq), stLFR-WGS, and Short Tandem Repeat (STR) analysis.

Results: Being assisted with IVF and EF technology, the couple successfully gave birth to twin sisters at 37 weeks of gestational age. The NonInvasive Prenatal Testing (NIPT) and Nuchal Translucency (NT) examination showed no detectable genetic abnormalities during pregnancy. However, the younger infant displayed growth retardation and feeding difficulties after birth, which was not observed in her twin sister. Further genetic counseling and diagnosis suggested that she is a Chimera with complex partial trisomy 21. The stLFR-WGS assay showed multiple CNV variations in Chr21 and STR analysis confirmed the paternal origin of the additional fragments.

Conclusion: It is rare for IVF-ET-assisted twin pregnancy to give birth to a girl with a complex combination of abnormal Chr21, which might result from paternal chromosome rearrangement during meiosis and mitosis.