How PGS/PGT-A laboratories succeeded in losing all credibility

Embryo drop-out rates in preimplantation genetic testing for aneuploidy (PGT-A): a retrospective data analysis from the DoLoRes study

PURPOSE

To evaluate the decline in transferable embryos in preimplantation genetic testing for aneuploidy (PGT-A) cycles due to (a) non-biopsable blastocyst quality, (b) failure of genetic analysis, (c) diagnosis of uniform numerical or structural chromosomal aberrations, and/or (d) chromosomal aberrations in mosaic constitution.

METHODS

This retrospective multicenter study comprised outcomes of 1562 blastocysts originating from 363 controlled ovarian stimulation cycles, respectively, 226 IVF couples in the period between January 2016 and December 2018. Inclusion criteria were PGT-A cycles with trophectoderm biopsy (TB) and next generation sequencing (NGS).

RESULTS

Out of 1562 blastocysts, 25.8% were lost due to non-biopsable and/or non-freezable embryo quality. In 10.3% of all biopsied blastocysts, genetic analysis failed. After exclusion of embryos with uniform or chromosomal aberrations in mosaic, only 18.1% of those originally yielded remained as diagnosed euploid embryos suitable for transfer. This translates into 50.4% of patients and 57.6% of stimulated cycles with no euploid embryo left for transfer. The risk that no transfer can take place rose significantly with a lower number of oocytes and with increasing maternal age. The chance for at least one euploid blastocyst/cycle in advanced maternal age (AMA)-patients was 33.3% compared to 52.1% in recurrent miscarriage (RM), 59.8% in recurrent implantation failure (RIF), and 60.0% in severe male factor (SMF).

CONCLUSIONS

The present study demonstrates that PGT-A is accompanied by high embryo drop-out rates. IVF-practitioners should be aware that their patients run a high risk of ending up without any embryo suitable for transfer after (several) stimulation cycles, especially in AMA patients. Patients should be informed in detail about the frequency of inconclusive or mosaic results, with the associated risk of not having an euploid embryo available for transfer after PGT-A, as well as the high cost involved in this type of testing.

Diagnosing chronic endometritis: when simplification fails to clarify

Reproductive immunology has grown in importance in recent years and has even developed into a discipline of its own within the field of reproductive medicine. Many aspects of reproductive failure such as repeated implantation failure or recurrent miscarriages are, meanwhile, seen as a consequence of aberrant expression of immunological factors. This is reflected by the increasing number of tests for assessing and quantifying different immune cell types as well as by a wide range of immune therapies offered to a clientele consisting of desperate patients requesting additional ‘IVF tools’: first, what is still usually disregarded is the enormous plasticity and fluctuation of most immune cells in the genital tract; second, their still poorly characterized functions in the endometrial cycle: further, their partially unknown role in embryo implantation and in establishing a pregnancy; and third, the fact that one of the fundamental hypotheses of reproductive immunology—of note—the Medawar concept or ‘Medawar's Paradox’ of semi-allogeneic graft embryo, is partially based on an erroneous assumption, i.e. the immunologic rejection and tolerance of an embryo. In the present opinion article, we comment on the diagnostic procedures and therapy approaches for chronic endometritis within the scope of reproductive medicine.

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

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

Time associations between U.S. birth rates and add-Ons to IVF practice between 2005-2016

Until 2010, the National Assisted Reproductive Technology Surveillance System (NASS) report, published annually by the Center for Disease Control and Prevention (CDC), demonstrated almost constantly improving live birth rates following fresh non-donor (fnd) in vitro fertilization (IVF) cycles. Almost unnoticed by profession and public, by 2016 they, however, reached lows not seen since 1996-1997. We here attempted to understand underlying causes for this decline. This study used publicly available IVF outcome data, reported by the CDC annually under Congressional mandate, involving over 90% of U.S. IVF centers and over 95% of U.S. IVF cycles. Years 2005, 2010, 2015 and 2016 served as index years, representing respectively, 27,047, 30,425, 21,771 and 19,137 live births in fnd IVF cycles. Concomitantly, the study associated timelines for introduction of new add-ons to IVF practice with changes in outcomes of fnd IVF cycles. Median female age remained at 36.0 years during the study period and center participation was surprisingly stable, thereby confirming reasonable phenotype stability. Main outcome measures were associations of specific IVF practice changes with declines in live IVF birth rates. Time associations were observed with increased utilization of "all-freeze" cycles (embryo banking), mild ovarian stimulation protocols, preimplantation genetic testing for aneuploidy (PGT-A) and increasing utilization of elective single embryo transfer (eSET). Among all add-ons, PGT-A, likely, affected fndIVF most profoundly. Though associations cannot denote causation, they can be hypothesis-generating. Here presented time-associations are compelling, though some of observed pregnancy and live birth loss may have been compensated by increases in frozen-thawed cycles and consequential pregnancies and live births not shown here. Pregnancies in frozen-thawed cycles, however, represent additional treatment cycles, time delays and additional costs. IVF live birth rates not seen since 1996-1997, and a likely continuous downward trend in U.S. IVF outcomes, therefore, mandate a reversal of current outcome trends, whatever ultimately the causes.

Noninvasive preimplantation genetic testing in assisted reproductive technology: current state and future perspectives

Invasive genetic screening of pre-implantation embryos via biopsied trophectoderm (TE) cells has been in use for more than 20 years, while its benefits in selecting euploid embryos remain controversial. Recent advances in the ability to process embryonic cell-free DNA (cfDNA) from blastocoel fluid (BF) and spent culture media (SCM) of blastocysts in a manner similar to that of a biopsied TE sample provide a potential alternative holding great promise for obtaining cytogenetic information of the embryos without intrusive biopsy of traditional biopsy-based pre-implantation genetic testing (PGT). Several studies have reported even higher diagnostic accuracy in non-invasive PGT (ni-PGT) than conventional PGT. However, there are still several technical challenges to be overcome before ni-PGT can be accepted as a reliable genomic information source of embryo. In this review, we have summarized the emergence and current state of ni-PGT, and discussed our own perspectives on their limitations and future prospect. There is still a long way to go before truly wide clinical application of ni-PGT.

Noninvasive Preimplantation Genetic Testing for Aneuploidy (niPGT-A): The first Brazilian baby

Recently, a new technology known as the Noninvasive Preimplantation Genetic Testing for Aneuploidy (niPGT-A) emerged, using cell-free DNA present in the spent culture media of human blastocysts. Unlike PGT-A, in which only trophectoderm cells are used, niPGT-A reflects the ploidy state of these cells and internal cell mass, suggesting that this new technology may be less prone to error, being more reliable than the invasive test. The aim of the present study was to report the first occurrence of childbirth following niPGT-A in Brazil.

Relationship between age and blastocyst chromosomal ploidy analyzed by noninvasive preimplantation genetic testing for aneuploidies (niPGT-A)

OBJECTIVE

To assess the relationship between human blastocyst chromosomal ploidy established by niPGT-A and increasing age.

METHODS

This is a prospective multicenter study carried out by ten assisted reproduction centers after their embryologists acquired training and validated their results with the previous use of niPGT-A. A total of 94 couples with indication for niPGT-A due to increase maternal age, male factor, repeated implantation failures, recurrent abortion or because they requested niPGT-A were included in this study. The couples had no karyotype abnormalities. After ICSI, the embryos were cultured until blastocyst stage using one or two step culture systems, single or sequential media respectively, at 37°C in an atmosphere of 6-7% CO2 and 5-20% O2 incubators. On day 3, we re-evaluated cleavage embryos to complete cumulus cells removal. The embryos were then cultured in individual well, with 20µl of medium under oil until they reached blastocyst stage. The blastocysts were vitrified and stored in liquid nitrogen. After that, the spent blastocyst culture medium (20µl) was transferred to a PCR tube and sent for analysis in the genetic laboratory, where it was stored at -80°C until sequencing. A total of 243 samples of spent blastocyst culture medium were collected on the 5th/6th day. Cell-free DNA secreted on culture medium was amplified using NICS Sample Preparation Kit (Yikon Genomics), based on the MALBAC technology. After whole genome amplification, the DNA was measured using a Qubit 2.0 fluorometer and subjected to next generation sequencing (NGS) using Illumina MiSeq® platform. The data were analyzed using the ChromGo® software (Yikon Genomics).

RESULTS

The mean age of the patients was 38±4.08 years with an interval of 20-44 years. The euploid was diagnosed in 36.4% (80/220) of cases, aneuploidy in 31.3% (69/220), and mosaicism in 32.3% (71/220; with ≥60% aneuploidy) of blastocysts. Mosaic values ranged from 29.8% to 33.8% in different age groups. Individually, the most frequent chromosomal abnormality was XXY (Klinefelter Syndrome) occurring in 18 cases, followed by chromosome 21 (trisomy/monosomy) in 8 cases. The niPGT-A data showed a ≥60% incidence of aneuploid cells in all cases of chromosomal mosaicism (n=71).

CONCLUSION

A high degree of mosaicism with aneuploidy cells was detected, and some hypotheses were suggested for this data (niPGT-A sensitivity in detecting the self-correction of chromosomal abnormalities phenomenon). However, it did not vary remarkably with age. On the other hand, euploidy levels had a negative correlation with age and aneuploidy levels had a positive relationship. This is the first report in the literature to relate chromosomal ploidy in blastocysts using niPGT-A and increasing patient age.

Medical research and reproductive medicine in an ethical context: a critical commentary on the paper dealing with uterine lavage published by Munné et al

A recent study published in Human Reproduction claimed that uterine lavage offers a non-surgical, minimally invasive strategy for the recovery of human embryos from fertile women who do not want or need IVF for medical reasons but who desire preimplantation genetic testing (PGT) for embryos. To prove this hypothesis, the researchers recruited dozens of young Mexican women. The prospective oocyte donors underwent ovarian stimulation to induce the production of multiple mature oocytes. Subsequently, these women were inseminated by donor semen. A few days later, the developing embryos were collected by uterine lavage (uterine flushing) and subjected to genetic testing for aneuploidies (PGT-A). Oocyte donors with persistently elevated hCG levels, indicating the implantation of one or more embryos after uterine lavage, had to undergo uterine curettage and/or treatment with methotrexate. A critical opinion paper discussing the aforementioned study was published by De Santis and colleagues and has raised critical issues that are largely technical in nature. However, this opinion paper neglects-from our point of view-critical issues of the Mexican study regarding ethical principles and moral standards in human research. These aspects are summarized below.

New perspectives with the use of noninvasive chromosome screening (NICS) in ART

After more than 20 years of use of preimplantation genetic tests for aneuploidies (PGS/PGT-A) there are still many problems related to the efficiency of this technique, most of them still without an adequate solution (Gleicher et al., 2018; Homer, 2019). From the clinical point of view, the benefits attributed to invasive PGT-A in the selection of euploid embryos remain controversial, especially due to the lack of scientific proof of its effectiveness in increasing live birth rates in various clinical situations, such as patients with advanced age, repeated implantation failures or recurrent miscarriages. In addition, evidence-based medicine also severely criticizes the rare randomized trials analyzing the clinical use of invasive PGT-A (Orvieto, 2016). If these criticisms were not enough, and undoubtedly one of the most important, it would be difficult to accurately assess the presence of embryonic mosaicism creating significant levels of false positive results, and worse, causing a real possibility of discarding healthy embryos. This makes the clinical application of PGT-A as a risky approach (Munné et al., 2017; Spinella et al., 2018). Another problem, not less important, would be the obligation to perform PGT-A by experienced embryologists, since otherwise the embryonic loss due to biopsy would be a frequent fact, something usually estimated below 10% but in some laboratories it may reach up to 30% of biopsied embryos (Munné, 2018). On the other hand, there are doubts about the future risks of invasive action of the usually 5-10 cell removed during biopsy for genetic diagnosis. Would there be repercussions for the health of these children? In animals, there are data suggesting that embryonic biopsies could be linked to changes in fetal neural tube or adrenal development (Wu et al., 2014; Zeng et al., 2013). Recently, Xu et al. (2016) described noninvasive chromosomal screening (NICS) by obtaining and sequencing free DNA dripped by embryos in the culture medium (without the need of embryo biopsy) creating a new non-aggressive and elegant perspective to preimplantation genetic diagnosis.

Human in vitro fertilisation and developmental biology: a mutually influential history

This article describes the origins and development of in vitro fertilisation (IVF) and how it was influenced by, and influenced, basic research in developmental biology. It describes the technical and social challenges that confronted the pioneers in this field of study, and the considerable progress that has been made since those early days. It also considers how IVF has contributed, and continues to contribute, to our understanding of early human development.

Worldwide live births following the transfer of chromosomally "Abnormal" embryos after PGT/A: results of a worldwide web-based survey

PURPOSE

Preimplantation genetic testing for aneuploidy (PGT-A) has become increasingly controversial since normal euploid births have been reported following transfer of embryos diagnosed as "abnormal." There is an increasing trend in transferring "abnormal" embryos; but it is still unknown how many IVF centers transfer "abnormal" embryos and with what efficiency.

METHODS

We performed a worldwide web-survey of IVF centers to elucidate PGT-A related practice patterns including transfer of human embryos found "abnormal" by PGT-A. Participating centers reflected in vitro fertilization (IVF) cycles in the USA, Canada, Europe, Asia, South America, and Africa.

RESULTS

One hundred fifty-one IVF centers completed the survey; 125 (83%) reported utilization of PGT-A. Europe had the highest utilization (32.3%), followed by the USA and Canada combined at 29.1%. The leading indications for PGT-A were advanced maternal age (77%), followed by recurrent implantation failure (70%), unexplained pregnancy loss (65%), and sex determination (25%); 14% of respondents used PGT-A for all of their IVF cycles; 20% of IVF units reported transfers of chromosomally "abnormal" embryos, and 56% of these took place in the USA, followed by Asia in 20%. Remarkably, 106 (49.3%) cycles resulted in ongoing pregnancies (n = 50) or live births (n = 56). Miscarriages were rare (n = 20; 9.3%).

CONCLUSIONS

The transfers of "abnormal" embryos by PGT-A offered robust pregnancy and live birth chances with low miscarriage rates. These data further strengthen the argument that PGT-A cannot reliably determine which embryos should or should not be transferred and leads to disposal of many normal embryos with excellent pregnancy potential.

Normalized Ploidy Following 20 Consecutive Blastocysts with Chromosomal Error: Healthy 46, XY Pregnancy with IVF after Intraovarian Injection of Autologous Enriched Platelet-derived Growth Factors

One explanation for why downstream gonadotropin protocol changes during IVF commonly arrive too late to have significant effects is that embryo development actually begins during oogenesis. Thus, efforts to modify the chromosomal status of blastocysts must address the ovarian milieu well in advance of follicular recruitment. A 42 year old woman with primary infertility of 3 year duration attended with her partner. Five previous IVF cycles had produced 20 embryos, but all had genetic abnormalities and no embryo transfer was performed. Karyotypes and all lab tests were normal for both partners. 3 months before her IVF here, she received isolated platelet-derived growth factors injected into both ovaries as a cell-free, enriched substrate. Genetic assessments were via whole genome amplification and DNA tagmentation and PCR adapter sequences. Comprehensive chromosomal screening was carried out by dual-indexed sequencing of pooled libraries on the MiSeq™ platform. From this IVF cycle one euploid 46, XY blastocyst was produced and vitrified on the day of trophectoderm biopsy. 9 days after frozen embryo transfer, serum human chorionic gonadotropin was 250 mIU/ml and a transvaginal ultrasound at 6 week gestation confirmed a single intrauterine pregnancy with fetal heart at 153/min. A healthy male infant was delivered by c-section at 39 weeks' gestation. While cellular and molecular events directing the oocyte-to-embryo transition are incompletely characterized, processes related to ovarian stem cell differentiation, mitochondrial dynamics, and mRNA storage, translation, and degradation likely are relevant. It appears that intraovarian application of autologous platelet-derived growth factors, when used before IVF, can impact oocyte integrity and facilitate euploid blastocyst development. Although research on intraovarian injection of autologous activated platelet rich plasma has already shown improved quantitative IVF responses, this is the first description of qualitative improvements in embryo genetics after intraovarian injection of autologous platelet-derived growth factors.

Artificial intelligence and machine learning for human reproduction and embryology presented at ASRM and ESHRE 2018

Sixteen artificial intelligence (AI) and machine learning (ML) approaches were reported at the 2018 annual congresses of the American Society for Reproductive Biology (9) and European Society for Human Reproduction and Embryology (7). Nearly every aspect of patient care was investigated, including sperm morphology, sperm identification, identification of empty or oocyte containing follicles, predicting embryo cell stages, predicting blastocyst formation from oocytes, assessing human blastocyst quality, predicting live birth from blastocysts, improving embryo selection, and for developing optimal IVF stimulation protocols. This represents a substantial increase in reports over 2017, where just one abstract each was reported at ASRM (AI) and ESHRE (ML). Our analysis reveals wide variability in how AI and ML methods are described (from not at all or very generic to fully describing the architectural framework) and large variability on accepted dataset sizes (from just 3 patients with 16 follicles in the smallest dataset to 661,060 images of 11,898 human embryos in one of the largest). AI and ML are clearly burgeoning methodologies in human reproduction and embryology and would benefit from early application of reporting standards.

Preimplantation genetic testing for aneuploidy (PGT-A): The biology, the technology and the clinical outcomes

Preimplantation genetic testing for aneuploidy (PGT-A) seeks to identify preimplantation embryos with a normal chromosome complement (euploid) during in vitro fertilisation (IVF). By sifting out embryos with abnormal chromosome numbers (aneuploid), PGT-A should theoretically improve pregnancy success. However, earlier versions of PGT-A were ineffective, and in some cases, detrimental, due to biopsy-induced trauma and because the technology at the time could analyse only a fraction of all chromosomes. More recently, the emergence of technologies enabling all chromosomes to be analysed and a switch to less traumatic blastocyst-stage biopsy have seen widespread uptake of PGT-A. Assessing the full impact of blastocyst biopsy PGT-A requires consideration of multiple factors, including embryonic mosaicism, sensitivity of the technological platform used, embryo loss during long-term in vitro culture, embryo cryopreservation and inter-clinic variability in expertise. Significantly, there hasnt yet been an appropriately designed randomised controlled trial (RCT) of blastocyst biopsy PGT-A analysed by intention-to-treat that accounts for all these parameters on a per-cycle basis. The three RCTs reporting benefits studied outcomes on a per-embryo transfer basis were small and underpowered and demonstrated benefits for a very select sub-group of good prognosis patients. The liberal use of this very expensive IVF add-on for other patient populations has not yet been shown to be effective, or indeed, without harm.