Utilization of preimplantation genetic testing in the USA

United States racial/ethnic disparities in PGT-A use: an analysis of 2014-2020 SART CORS database

BACKGROUND

The use of preimplantation genetic testing for aneuploidy (PGT-A) allows for the selection of euploid embryos and has been thought to improve outcomes in ART, particularly in women ≥ 35 years old. However, little is known regarding PGT-A utilization among minority women in the United States (US). The objective of this study was to determine the trend of utilization of PGT-A in the US among minority women.

METHODS

We conducted a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) database. We included initial autologous ART cycles performed between 2014 and 2020. We assessed the rate of PGT-A utilization by race/ethnicity.

RESULTS

This study included 150,604 PGT-A and 287,979 non-PGT-A initial autologous cycles. The overall trend of PGT-A utilization, regardless of race/ethnicity, increased from 11.5 to 49.0% (p < 0.001) over seven years. Of all ART cycles, 33% of White women used PGT-A, in comparison to 24% of Black women, 31% of Hispanic women, and 44% of Asian women (p < 0.001). Multiple Logistic Regression (MLR) determined race/ethnicity as an independent predictor of PGT-A utilization when adjusting for age, BMI, and AMH (p < 0.001). Compared to White women, MLR showed that Black and Hispanic women were 35% and 16% less likely to use PGT-A (aOR = 0.65, 95% CI 0.63-0.67, and aOR = 0.86, 95% CI 0.84-0.88, respectively, p < 0.001). In contrast, Asian women were 41% (aOR = 1.41, 95% CI 1.39-1.44) more likely to use PGT-A (p < 0.001). Overall, regardless of race/ethnicity, women 35 and older were 71% (aOR = 1.71, 95% CI 1.69-1.74) more likely to use PGT-A compared to women younger than 35 (p < 0.001).

CONCLUSION

Despite a significant increase in overall PGT-A utilization in the US over 7 years, utilization has been consistently less in ART cycles for Black and Hispanic women, in comparison to White women. This is in marked contrast to an increase in PGT-A utilization in cycles for Asian women.

How will IVF be delivered in 25 years' time?

As the practice of IVF evolves, the need to bring its benefits to more people with diverse treatment indications looms as the field's biggest challenge. What will the delivery of IVF look like in 25 years' time as it meets this challenge?

Preimplantation genetic testing and disorders of placental implantation: a systematic review and meta-analysis

PURPOSE

To evaluate whether embryo biopsy for preimplantation genetic testing (PGT) during in vitro fertilization (IVF) increases the risk of disorders related to abnormal placental implantation.

METHODS

A systematic search of Medline, Embase, and Web of Science was performed on February 17, 2023, and identified studies on placental implantation anomalies following PGT in IVF patients. The primary outcome was placenta accreta spectrum (PAS), while secondary outcomes included placental abruption, placenta previa, preterm premature rupture of membranes (PPROM), and hypertensive pregnancy disorders. Only peer-reviewed randomized controlled trials, cohort, case-control, and cross-sectional studies in English were considered. Two reviewers independently screened citations, extracted data, and assessed study quality. Data analysis was performed using RevMan 5.4.

RESULTS

Of 282 citations retrieved by our search, 8 studies met inclusion criteria. There was no statistically significant difference in PAS risk between groups (aggregated OR 0.78, 95% CI 0.22-2.76, P = 0.70). Amongst secondary outcomes, mean BMI was lower in PGT patients (mean difference - 0.57, 95% CI - 0.98 to - 0.17, P = 0.005), and PPROM rates were higher (OR 1.29, 95% CI 1.04-1.60, P = 0.02). Other secondary outcomes showed no significant differences.

CONCLUSION

Embryo biopsy for PGT in IVF was not associated with an increased risk of PAS. However, PGT was more commonly performed in patients with lower BMI, and an elevated risk of PPROM was observed, primarily driven by a single study. Further investigation is needed to clarify this finding and its implications.

Success rates with preimplantation genetic testing for aneuploidy in good prognosis patients are dependent on age

OBJECTIVE

To evaluate cumulative live birth after preimplantation genetic testing for aneuploidy (PGT-A) with next generation sequencing (NGS) compared with morphology alone among patients aged 21-40 years undergoing single blastocyst transfer.

DESIGN

Retrospective cohort study.

SUBJECTS

Patients aged 21-40 years undergoing first autologous retrieval cycles resulting in ≥5 fertilized oocytes, with subsequent single blastocyst transfer in Society for Assisted Reproductive Technology clinics from 2016-2019.

EXPOSURE

PGT-A using NGS.

MAIN OUTCOME MEASURES

The primary outcome was cumulative live birth per retrieval. Secondary outcomes included clinical pregnancy, miscarriage, and live birth per transfer.

RESULTS

A total of 56,469 retrieval cycles were included in the analysis. Retrieval cycles were stratified based on age (<35, 35-37, and 38-40 years) and exposure to PGT-A with NGS. Modified Poisson regression modeling was used to evaluate the association between PGT-A and cumulative live birth per retrieval while controlling for covariates. In this cohort, most cycles did not use PGT-A (n = 49,608; 88%). After adjusting for covariates, the use of PGT-A was associated with a slightly lower cumulative live birth in individuals aged <35 years (risk ratio [RR]: 0.96; 95% CI: 0.93-0.99) compared with no PGT, but higher cumulative live birth in ages 35-37 years (RR: 1.04; 95% CI: 1.00-1.08), and 38-40 years (RR: 1.14; 95% CI: 1.07-1.20). A subgroup analysis limited to freeze-all cycles (n = 29,041) showed that PGT-A was associated with higher cumulative live birth in individuals aged ≥35 years and was similar to no PGT in individuals aged <35 years. Miscarriage was significantly less likely in individuals aged ≥35 years using PGT-A compared with no PGT-A.

CONCLUSION

In this large national database study, success rates in cycles using PGT-A were dependent on age. Cumulative live birth was observed to be significantly less likely in PGT-A cycles among individuals aged <35 years and more likely among individuals aged 38-40 years, compared with no PGT-A. In individuals with no fresh transfer, results were similar. Moreover, miscarriage was significantly less likely with PGT-A among individuals aged 35-40 years in a subgroup analysis of freeze-all cycles.

PGT-A: what's it for, what's wrong?

PGT-A, what's it for? Considering the increase in fetal aneuploidies with a woman's age and the high number of miscarriages associated with fetal karyotype anomalies, the concept of selecting IVF embryos based on their karyotype in order to transfer only euploid embryos and eliminate aneuploid ones was proposed. Preimplantation genetic testing for aneuploidy (PGT-A) was then established, nearly 30 years ago, with the expectation that the transfer of euploid embryos would lead to a significant improvement in medically assisted reproduction (MAR) outcomes. PGT-A, what's wrong? Despite the practice and widespread use, PGT-A has not consistently proven its effectiveness. The clinical value of PGT-A remains controversial. The initial studies reported an increase in MAR outcomes. However, these studies used embryo transfer as the reference point. More recent studies, which use intention-to-treat as the reference point, show, at best, slight improvements and, at worst, a reduction in the considered IVF outcomes. In this article, we attempt to answer two key questions: "What is it for?" and "What's wrong with PGT-A?". We also explore some of the ethical issues raised by these conclusions. Ultimately, we suggest that PGT-A should no longer be offered to infertile couples.

Advancements and Challenges in Preimplantation Genetic Testing for Aneuploidies: In the Pathway to Non-Invasive Techniques

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

Genetics in Reproductive Medicine

Thanks to advances in technology, genetic testing is now available to explore the causes of infertility and to assess the risk of a given couple passing on a genetic disorder to their offspring. This allows at-risk couples to make an informed decision when opting for assisted reproduction and allows professionals to offer pre-implantation diagnosis when appropriate. Genetic screening of an infertile couple has thus become standard practice for an appropriate diagnosis, treatment, and prognostic assessment. This review aims to highlight the conditions under which genetic screening plays a role in improving reproductive outcomes for infertile couples.

Clinical-grade whole genome sequencing-based haplarithmisis enables all forms of preimplantation genetic testing

High-throughput sequencing technologies have increasingly led to discovery of disease-causing genetic variants, primarily in postnatal multi-cell DNA samples. However, applying these technologies to preimplantation genetic testing (PGT) in nuclear or mitochondrial DNA from single or few-cells biopsied from in vitro fertilised (IVF) embryos is challenging. PGT aims to select IVF embryos without genetic abnormalities. Although genotyping-by-sequencing (GBS)-based haplotyping methods enabled PGT for monogenic disorders (PGT-M), structural rearrangements (PGT-SR), and aneuploidies (PGT-A), they are labour intensive, only partially cover the genome and are troublesome for difficult loci and consanguineous couples. Here, we devise a simple, scalable and universal whole genome sequencing haplarithmisis-based approach enabling all forms of PGT in a single assay. In a comparison to state-of-the-art GBS-based PGT for nuclear DNA, shallow sequencing-based PGT, and PCR-based PGT for mitochondrial DNA, our approach alleviates technical limitations by decreasing whole genome amplification artifacts by 68.4%, increasing breadth of coverage by at least 4-fold, and reducing wet-lab turn-around-time by ~2.5-fold. Importantly, this method enables trio-based PGT-A for aneuploidy origin, an approach we coin PGT-AO, detects translocation breakpoints, and nuclear and mitochondrial single nucleotide variants and indels in base-resolution.

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.

One size does not fit all: the personal nature of completed embryo donation

PURPOSE

To assess factors associated with embryo donation among individuals interested in donation in the United States.

METHODS

An invitation to complete the 123-item survey was emailed from June to September 2022 to patients at a private practice fertility clinic with interest in donation at the time of IVF. Survey questions included disposition decision, attitudes about embryo status and genetic relatedness, donation disclosure, ideal donation arrangement, and decision satisfaction.

RESULTS

Three hundred thirty-seven completed the survey. Two hundred thirty donated to another person(s), 75 discarded embryos, 25 remained undecided, and disposition was unknown for 7 respondents. There were no demographic differences between groups based on final disposition or use of donor gametes. Few gamete recipients were interested in donation due to biological attachment to embryos. Final embryo disposition was associated with religious factors, not wanting to waste embryos, and storage fee concerns. Final disposition was also significantly associated with concern about donor-conceived children's (DCP) welfare, being denied the ability to complete donation, personal IVF outcomes, financial or legal issues, future contact with DCP, cognitive appraisal of disposition, beliefs about embryos, someone else raising their genetic child, anonymity, and beliefs about DCP not knowing genetic relationships (p < .001). Donation to others was associated with less regret and greater satisfaction with the emotional/medical aspects of donation and counseling compared to those who discarded embryos (p < .001).

CONCLUSION

The decision to donate embryos to another person(s) is complex. Counseling that considers individual circumstances, values, and evolving dynamics may facilitate informed decision-making for those navigating infertility treatment, family building, and embryo disposition.

Impact of double trophectoderm biopsy on reproductive outcomes following single euploid blastocyst transfer

OBJECTIVES

To study the effect of double trophectoderm biopsy on clinical outcomes following single euploid blastocyst transfer.

STUDY DESIGN

Retrospective cohort study of 2046 single euploid frozen-thawed blastocyst transfers from January 2015 to June 2022 in a single centre. All patients undergoing a frozen-thawed embryo transfer (FTET) cycle with euploid blastocysts, biopsied for any indication, were included. The outcomes were compared for blastocysts which were biopsied and vitrified once (Group 1, n = 1684), biopsied once but vitrified twice (Group 2, n = 312) and biopsied and vitrified twice (Group 3n = 50). We adjusted for confounders and performed subgroup analysis for PGT-A, PGT-M and PGT-SR cycles. The primary outcome was live birth rate. Secondary outcomes included pregnancy, clinical pregnancy, birthweight and sex ratio.

RESULTS

After adjusting for confounders (previous failed euploid implantations, embryo quality and day of biopsy), embryos which were biopsied twice had lower OR for clinical pregnancy (0.48, CI 0.26-0.88, p = 0.019) and for live birth (0.50 CI 0.27-0.92, p = 0.025) compared to controls. Embryos which were biopsied once but vitrified twice had no different ORs for all reproductive outcomes compared to controls. No significant difference was observed for neonatal birthweight or sex ratio amongst the three groups. This is a retrospective single centre study with inherent bias and results may not be transferable to all settings.

CONCLUSION

This study is the largest to date assessing the outcomes of FTET cycles following double trophectoderm biopsy. The results are in keeping with the existing literature and can be incorporated into patient counselling. Whilst double biopsy seems to adversely impact LBR, it is only one of the many factors that can affect success rates. The subfertility background and embryo characteristics should not be overlooked. This study provides reassuring evidence since double biopsied embryos still result in live births with no difference in sex ratio or birthweight. However, long term follow up of the off-springs is lacking and should be reported in future studies.

Effect of time post warming to embryo transfer on human blastocyst metabolism and pregnancy outcome

PURPOSE

This study is aiming to test whether variation in post warming culture time impacts blastocyst metabolism or pregnancy outcome.

METHODS

In this single center retrospective cohort study, outcomes of 11,520 single frozen embryo transfer (FET) cycles were analyzed from January 2015 to December 2020. Patient treatments included both natural and programmed cycles. Time categories were determined using the time between blastocyst warming and embryo transfer: 0 (0- <1h), 1 (1-<2h), 2 (2-<3h), 3(3-<4h), 4 (4-<5), 5 (5-<6), 6 (6-<7) and 7 (7-8h). Non-invasive metabolic imaging of discarded human blastocysts for up to 10h was also performed using Fluorescence lifetime imaging microscopy (FLIM) to examine for metabolic perturbations during culture.

RESULTS

The mean age of patients across all time categories were comparable (35.6 ± 3.9). Live birth rates (38-52%) and miscarriage rate (5-11%) were not statistically different across post-warming culture time. When assessing pregnancy outcomes based on the use of PGT-A, miscarriage and live birth rates were not statistically different across culture hours in both PGT-A and non-PGT cycles. Further metabolic analysis of blastocysts for the duration of 10h of culture post warming, revealed minimal metabolic changes of embryos in culture.

CONCLUSION

Overall, our results show that differences in the time of post warming culture have no significant impact on miscarriage or live birth rate for frozen embryo transfers. This information can be beneficial for clinical practices with either minimal staffing or a high number of patient cases.

Public Attitudes, Interests, and Concerns Regarding Polygenic Embryo Screening

Importance

Polygenic embryo screening (PES) is a novel technology that estimates the likelihood of developing future conditions (eg, diabetes or depression) and traits (eg, height or cognitive ability) in human embryos, with the goal of selecting which embryos to use. Given its commercial availability and concerns raised by researchers, clinicians, bioethicists, and professional organizations, it is essential to inform key stakeholders and relevant policymakers about the public's perspectives on this technology.

Objective

To survey US adults to examine general attitudes, interests, and concerns regarding PES use.

Design, Setting, and Participants

For this survey study, data were collected from 1 stratified sample and 1 nonprobability sample (samples 1 and 2, respectively) between March and July 2023. The surveys measured approval, interest, and concerns regarding various applications of PES. In the second sample, presentation of a list of potential concerns was randomized (presented at survey onset vs survey end). The survey was designed using Qualtrics and distributed to participants through Prolific, an online sampling firm. Sample 1 was nationally representative with respect to gender, age, and race and ethnicity; sample 2 was recruited without specific demographic criteria. Analyses were conducted between March 2023 and February 2024.

Main Outcomes and Measures

Participants reported their approval, interest, and concerns regarding various applications of PES and outcomes screened (eg, traits and conditions). Statistical analysis was conducted using independent samples t tests and repeated-measures analyses of variance.

Results

Of the 1435 respondents in sample 1, demographic data were available for 1427 (mean [SD] age, 45.8 [16.0] years; 724 women [50.7%]). Among these 1427 sample 1 respondents, 1027 (72.0%) expressed approval for PES and 1169 (81.9%) expressed some interest in using PES if already undergoing in vitro fertilization (IVF). Approval among these respondents for using PES for embryo selection was notably high for physical health conditions (1109 [77.7%]) and psychiatric health conditions (1028 [72.0%]). In contrast, there was minority approval for embryo selection based on PES for behavioral traits (514 [36.0%]) and physical traits (432 [30.3%]). Nevertheless, concerns about PES leading to false expectations and promoting eugenic practices were pronounced, with 787 of 1422 (55.3%) and 780 of 1423 (54.8%) respondents finding them very to extremely concerning, respectively. Sample 2 included 192 respondents (mean [SD] age 37.7 [12.2] years; 110 men [57.3%]). These respondents were presented concerns at survey onset (n = 95) vs survey end (n = 97), which was associated with less approval (28-percentage point decrease) and more uncertainty (24 percentage-point increase) but with only slightly higher disapproval (4 percentage-point increase).

Conclusions and Relevance

These findings suggest that it is critical for health care professionals and medical societies to consider and understand the perspectives of diverse stakeholders (eg, patients undergoing IVF, clinicians, and the general public), given the absence of regulation and the recent commercial availability of PES.

Multiple embryo manipulations in PGT-A cycles may result in inferior clinical outcomes

RESEARCH QUESTION

Do embryos that undergo a thaw, biopsy and re-vitrification (TBR) for pre-implantation genetic testing for aneuploidy (PGT-A) have different ploidy and transfer outcomes compared with fresh biopsied embryos?

DESIGN

Retrospective cohort study of all embryos that underwent the following procedures: fresh biopsy for PGT-A (fresh biopsy); embryos that were warmed, biopsied for PGT-A and re-vitrified (single biopsy TBR); embryos with a no signal result after initial biopsy that were subsequently warmed, biopsied and re-vitrified (double biopsy TBR). The patients who underwent transfers of those embryos at a single academic institution between March 2013 and December 2021 were also studied.

RESULTS

About 30% of embryos planned for TBR underwent attrition. Euploidy rates were similar after biopsy: fresh biopsy (42.7%); single biopsy TBR (47.5%) (adjusted RR: 0.99, 0.88 to 1.12); and double biopsy TBR 50.3% (adjusted RR: 0.99, 0.80 to 1.21). Ongoing pregnancy over 8 weeks was not statistically significant (double biopsy TBR: 6/19 [31.6%] versus fresh biopsy: 650/1062 [61.2%]) (adjusted RR 0.52, 95% CI 0.26 to 1.03). The miscarriage rate increased (double biopsy TBR: 4/19 [21.1%] versus fresh biopsy: 66/1062 [6.2%])(RR 3.39, 95% CI 1.38 to 8.31). Live birth rate was also lower per transfer for the double biopsy TBR group (double biopsy TBR [18.75%] versus fresh biopsy [53.75%]) (RR 0.35, 95% CI 0.12 to 0.98), though not after adjustment (adjusted RR 0.37, 95% CI 0.13 to 1.09). These differences were not seen when single biopsy TBR embryos were transferred.

CONCLUSIONS

Embryos that undergo TBR have an equivalent euploidy rate to fresh biopsied embryos. Despite that, double biopsy TBR embryos may have impaired transfer outcomes.

Implicit bias in diagnosing mosaicism amongst preimplantation genetic testing providers: results from a multicenter study of 36 395 blastocysts

STUDY QUESTION

Does the diagnosis of mosaicism affect ploidy rates across different providers offering preimplantation genetic testing for aneuploidies (PGT-A)?

SUMMARY ANSWER

Our analysis of 36 395 blastocyst biopsies across eight genetic testing laboratories revealed that euploidy rates were significantly higher in providers reporting low rates of mosaicism.

WHAT IS KNOWN ALREADY

Diagnoses consistent with chromosomal mosaicism have emerged as a third category of possible embryo ploidy outcomes following PGT-A. However, in the era of mosaicism, embryo selection has become increasingly complex. Biological, technical, analytical, and clinical complexities in interpreting such results have led to substantial variability in mosaicism rates across PGT-A providers and clinics. Critically, it remains unknown whether these differences impact the number of euploid embryos available for transfer. Ultimately, this may significantly affect clinical outcomes, with important implications for PGT-A patients.

STUDY DESIGN, SIZE, DURATION

In this international, multicenter cohort study, we reviewed 36 395 consecutive PGT-A results, obtained from 10 035 patients across 11 867 treatment cycles, conducted between October 2015 and October 2021. A total of 17 IVF centers, across eight PGT-A providers, five countries and three continents participated in the study. All blastocysts were tested using trophectoderm biopsy and next-generation sequencing. Both autologous and donation cycles were assessed. Cycles using preimplantation genetic testing for structural rearrangements were excluded from the analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The PGT-A providers were randomly categorized (A to H). Providers B, C, D, E, F, G, and H all reported mosaicism, whereas Provider A reported embryos as either euploid or aneuploid. Ploidy rates were analyzed using multilevel mixed linear regression. Analyses were adjusted for maternal age, paternal age, oocyte source, number of embryos biopsied, day of biopsy, and PGT-A provider, as appropriate. We compared associations between genetic testing providers and PGT-A outcomes, including the number of chromosomally normal (euploid) embryos determined to be suitable for transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean maternal age (±SD) across all providers was 36.2 (±5.2). Our findings reveal a strong association between PGT-A provider and the diagnosis of euploidy and mosaicism. Amongst the seven providers that reported mosaicism, the rates varied from 3.1% to 25.0%. After adjusting for confounders, we observed a significant difference in the likelihood of diagnosing mosaicism across providers (P < 0.001), ranging from 6.5% (95% CI: 5.2-7.4%) for Provider B to 35.6% (95% CI: 32.6-38.7%) for Provider E. Notably, adjusted euploidy rates were highest for providers that reported the lowest rates of mosaicism (Provider B: euploidy, 55.7% (95% CI: 54.1-57.4%), mosaicism, 6.5% (95% CI: 5.2-7.4%); Provider H: euploidy, 44.5% (95% CI: 43.6-45.4%), mosaicism, 9.9% (95% CI: 9.2-10.6%)); and Provider D: euploidy, 43.8% (95% CI: 39.2-48.4%), mosaicism, 11.0% (95% CI: 7.5-14.5%)). Moreover, the overall chance of having at least one euploid blastocyst available for transfer was significantly higher when mosaicism was not reported, when we compared Provider A to all other providers (OR = 1.30, 95% CI: 1.13-1.50). Differences in diagnosing and interpreting mosaic results across PGT-A laboratories raise further concerns regarding the accuracy and relevance of mosaicism predictions. While we confirmed equivalent clinical outcomes following the transfer of mosaic and euploid blastocysts, we found that a significant proportion of mosaic embryos are not used for IVF treatment.

LIMITATIONS, REASONS FOR CAUTION

Due to the retrospective nature of the study, associations can be ascertained, however, causality cannot be established. Certain parameters such as blastocyst grade were not available in the dataset. Furthermore, certain platform-related and clinic-specific factors may not be readily quantifiable or explicitly captured in our dataset. As such, a full elucidation of all potential confounders accounting for variability may not be possible.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings highlight the strong need for standardization and quality assurance in the industry. The decision not to transfer mosaic embryos may ultimately reduce the chance of success of a PGT-A cycle by limiting the pool of available embryos. Until we can be certain that mosaic diagnoses accurately reflect biological variability, reporting mosaicism warrants utmost caution. A prudent approach is imperative, as it may determine the difference between success or failure for some patients.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Torres Quevedo Grant, awarded to M.P. (PTQ2019-010494) by the Spanish State Research Agency, Ministry of Science and Innovation, Spain. M.P., L.B., A.R.L., A.L.R.d.C.L., N.P.P., M.P., D.S., F.A., A.P., B.M., L.D., F.V.M., D.S., M.R., E.P.d.l.B., A.R., and R.V. have no competing interests to declare. B.L., R.M., and J.A.O. are full time employees of IB Biotech, the genetics company of the Instituto Bernabeu group, which performs preimplantation genetic testing. M.G. is a full time employee of Novagen, the genetics company of Cegyr, which performs preimplantation genetic testing.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of pre-implantation genetic testing for aneuploidy outcomes in patients without infertility undergoing in vitro fertilization compared to infertile controls

PURPOSE

To evaluate pre-implantation genetic testing for aneuploidy (PGT-A) outcomes in patients without infertility compared to infertile patients.

METHODS

We performed a retrospective cohort study of all patients without an infertility diagnosis ("fertile" patients) who utilized PGT-A at a large university-affiliated fertility center between 2016 and 2021. Fertile patients were 1-to-3 matched to infertile controls by age and number of oocytes retrieved. The primary outcome was blastocyst aneuploidy rate. Secondary outcomes included ovarian reserve markers, laboratory outcomes, and other PGT-A outcomes [rates of euploidy, mosaicism, and potentially transferrable (euploid + mosaic) embryos].

RESULTS

283 fertile and 849 infertile patients were included. Median age, anti-Mullerian hormone, and day 2 estradiol levels were equivalent among groups; day 2 follicle-stimulating hormone levels were higher in fertile patients (6.9 vs. 6.5 IU/mL, p < 0.01). The aneuploidy rate was similar among fertile and infertile patients (33.7% vs. 31.8%, p = 0.11); the euploidy rate was higher (50.8% vs. 47.0%, p < 0.01), and the mosaicism rate was lower in fertile patients (13.3% vs. 19.2%, p < 0.01). The rate of transferrable embryos was similar among groups (64.0% vs. 66.3%, p = 0.07), as was the percentage of patients yielding ≥ 1 euploid embryo (90.1% vs. 87.3%, p = 0.25). When controlling for significant covariates, multiple linear regression showed that aneuploidy rate was equivalent in both cohorts.

CONCLUSION

Aneuploidy rate was similar in fertile and infertile patients. Fertile patients had slightly higher euploidy and lower mosaicism than infertile patients. Still, compared to fertile patients, infertile patients had equivalent rates of transferrable embryos and were just as likely to yield ≥ 1 euploid embryo.

Divergence Between Clinician and Patient Perspectives on Polygenic Embryo Screening: A Qualitative Study

Objective

To explore and compare the perspectives of clinicians and patients on polygenic embryo screening.

Design

Qualitative.

Subjects

Fifty-three participants: 27 reproductive endocrinology and infertility specialists and 26 patients currently undergoing in vitro fertilization or had done so within the last five years.

Main Outcome Measures

Qualitative thematic analysis of interview transcripts.

Results

Both clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more often than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer polygenic embryo screening to patients or were willing to do so only under certain circumstances, while many patients expressed interest in polygenic embryo screening. Both sets of stakeholders envisioned multiple potential benefits or uses of polygenic embryo screening; the most common included selection and/or prioritization of embryos, receipt of more information about embryos, and preparation for the birth of a predisposed or "affected" child. Both sets of stakeholders also raised multiple potential, interrelated concerns about polygenic embryo screening. The most common concerns among both sets of stakeholders included the potential for different types of "biases" - most often in relation to selection of embryos with preferred genetic chances of traits -, the probabilistic nature of polygenic embryo screening that can complicate patient counseling and/or lead to excessive cycles of in vitro fertilization, and a lack of data from long-term prospective studies supporting the clinical use of polygenic embryo screening.

Conclusion

Despite patients' interest in polygenic embryo screening, clinicians feel such screening is premature for clinical application. Though now embryos can be screened for their genetic chances of developing polygenic conditions and traits, many clinicians and patients maintain different attitudes depending on what is specifically screened, despite the blurry distinction between conditions and traits. Considerations raised by these stakeholders may help guide professional societies as they consider developing guidelines to navigate the uncertain terrain of polygenic embryo screening, which is already commercially available.

PGT-A: Houston, we have a problem

Preimplantation genetic testing for aneuploidy (PGT-A) is a common add-on to IVF cycles. As it is presently performed, PGT-A relies on whole genome amplification of small amounts of DNA from cells removed from the trophectoderm (TE) of a blastocyst for determination of gain or loss of chromosomal material by next-generation sequencing. Whole genome amplification may introduce artifacts such as allele dropout and loss of heterozygosity in up to 25% of cases. In addition, the high prevalence of mosaicism in human embryos is a complicating factor in interpreting the results of PGT-A screening. In the presence of mosaicism, biopsy of TE cells cannot provide accurate results regarding the chromosomal make-up of the inner cell mass. The available clinical data suggest that PGT-A is probably harmful when IVF outcomes are analyzed by intention to treat or by live birth rate per cycle started rather than per embryo transfer, especially in women with three or fewer blastocysts. In addition, hypothesized advantages of reduced spontaneous abortion rate and reduced time to conception may be modest at best.

Genetics in reproductive endocrinology and infertility

Tremendous advances in genetics have transformed the field of reproductive endocrinology and infertility over the last few decades. One of the most prominent advances is preimplantation genetic testing (PGT), which allows for the screening of embryos obtained during in vitro fertilization before transfer. Moreover, PGT can be performed for aneuploidy screening, detection of monogenic disorders, or exclusion of structural rearrangements. Refinement of biopsy techniques, such as obtaining samples at the blastocyst rather than the cleavage stage, has helped optimize results from PGT, and technological advances, including next-generation sequencing, have made PGT more efficient and accurate. The continued evolution of the approach to PGT has the potential to further enhance the accuracy of results, expand the application to other conditions, and increase access by reducing cost and improving efficiency.

Predicted probabilities of live birth following assisted reproductive technology using United States national surveillance data from 2016 to 2018

BACKGROUND

As the use of in vitro fertilization continues to increase in the United States, up-to-date models that estimate cumulative live birth rates after multiple oocyte retrievals and embryo transfers (fresh and frozen) are valuable for patients and clinicians weighing treatment options.

OBJECTIVE

This study aimed to develop models that generate predicted probabilities of live birth in individuals considering in vitro fertilization based on demographic and reproductive characteristics.

STUDY DESIGN

Our population-based cohort study used data from the National Assisted Reproductive Technology Surveillance System 2016 to 2018, including 196,916 women who underwent 207,766 autologous embryo transfer cycles and 25,831 women who underwent 36,909 donor oocyte transfer cycles. We used data on autologous in vitro fertilization cycles to develop models that estimate a patient's cumulative live birth rate after all embryo transfers (fresh and frozen) within 12 months after 1, 2, and 3 oocyte retrievals in new and returning patients. Among patients using donor oocytes, we estimated the cumulative live birth rate after their first, second, and third embryo transfers. Multinomial logistic regression models adjusted for age, prepregnancy body mass index (imputed for 18% of missing values), parity, gravidity, and infertility diagnoses were used to estimate the cumulative live birth rate.

RESULTS

Among new and returning patients undergoing autologous in vitro fertilization, female age had the strongest association with cumulative live birth rate. Other factors associated with higher cumulative live birth rates were lower body mass index and parity or gravidity ≥1, although results were inconsistent. Infertility diagnoses of diminished ovarian reserve, uterine factor, and other reasons were associated with a lower cumulative live birth rate, whereas male factor, tubal factor, ovulatory disorders, and unexplained infertility were associated with a higher cumulative live birth rate. Based on our models, a new patient who is 35 years old, with a body mass index of 25 kg/m2, no previous pregnancy, and unexplained infertility diagnoses, has a 48%, 69%, and 80% cumulative live birth rate after the first, second, and third oocyte retrieval, respectively. Cumulative live birth rates are 29%, 48%, and 62%, respectively, if the patient had diminished ovarian reserve, and 25%, 41%, and 52%, respectively, if the patient was 40 years old (with unexplained infertility). Very few recipient characteristics were associated with cumulative live birth rate in donor oocyte patients.

CONCLUSION

Our models provided estimates of cumulative live birth rate based on demographic and reproductive characteristics to help inform patients and providers of a woman's probability of success after in vitro fertilization.

Does PGT-A affect cumulative live birth rate?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Aneuploidy screening after preimplantation genetic testing: a national survey of physician knowledge and practice

PURPOSE

To assess the knowledge of generalist OB/GYN providers on aneuploidy screening recommendations for patients who utilized preimplantation genetic testing, and to survey providers' current practice habits.

METHODS

A 12-question survey was distributed by email to OB/GYN physicians in the USA. Demographic information was also collected.

RESULTS

A total of 178 survey responses were included for analysis. Sixty-seven percent correctly identified the current ACOG recommendation to offer additional aneuploidy screening/invasive diagnostic testing regardless of PGT status, and 66% said their practice is consistent with this recommendation. Ninety-one percent of responders correctly answered that in vitro fertilization does not always include PGT and 63% of responders were able to correctly identify the 3 available types of PGT. Thirty-three percent (n = 58) were attending physicians, and 67% (n = 120) were resident physicians. Most participants (81%, n = 145) stated they have been in practice 0-9 years, and the remaining 19% (n = 33) stated they have been in practice ≥ 10 years.

CONCLUSION

Significant knowledge gaps of PGT and aneuploidy screening recommendations after PGT exist among generalist OB/GYN physicians. Efforts should be made to educate providers on the importance of offering aneuploidy screening and diagnostic testing to patients who utilized PGT to improve patient care.

Fresh vs. frozen embryo transfer: new approach to minimize the limitations of using national surveillance data for clinical research

OBJECTIVE

To assess the benefit of frozen vs. fresh elective single embryo transfer using traditional and novel methods of controlling for confounding.

DESIGN

Retrospective cohort study using data from the National Assisted Reproductive Technology Surveillance System.

SETTING

Not applicable.

PATIENT(S)

A total of 44,750 women aged 20-35 years undergoing their first lifetime oocyte retrieval and embryo transfer in 2016-2017, who had ≥4 embryos cryopreserved.

INTERVENTION(S)

Fresh elective single embryo transfer and frozen elective single embryo transfer.

MAIN OUTCOME MEASURE(S)

The primary outcome was a singleton live birth. Secondary outcomes included rates of total live birth (singleton plus multiple gestations), twin live birth, clinical intrauterine gestation, total pregnancy loss, biochemical pregnancy, and ectopic pregnancy. Outcomes for infants included gestational age at delivery, birth weight, and being small for gestational age.

RESULT(S)

The eligibility criteria were met by 6,324 fresh and 2,318 frozen cycles. Patients undergoing fresh and frozen transfer had comparable mean age (30.69 [standard deviation {SD} 0.08] years vs. 31.06 [SD 0.08] years) and body mass index (24.76 [SD 0.20] vs. 25.65 [SD 0.15]); however, women in the frozen cohort created more embryos (8.1 [SD 0.12] vs. 6.8 [SD 0.08]). Singleton live birth rates in the fresh vs. frozen groups were 51.4% vs. 48.8% (risk ratio 1.05; 95% confidence interval [CI], 1.00-1.10). After adjustment with a log-linear regression model and propensity score analysis, the difference in singleton live birth rates remained nonsignificant (adjusted risk ratio, 1.05; 95% CI, 0.97-1.14 and 1.02; 95% CI, 0.96-1.08, respectively). A novel dynamical model confirmed inherent fertility (probability of ever achieving a pregnancy) was balanced between groups (odds ratio, 1.23; 95% CI 0.78-1.95]). The per-cycle probability of singleton live birth was not different between groups (odds ratio 1.11 [95% CI 0.94-1.3]).

CONCLUSION(S)

In this retrospective cohort study of fresh vs. frozen elective single embryo transfer, there was no statistically significant difference in singleton live birth rate after adjustment using log-linear models and propensity score analysis. The successful application of a novel dynamical model, which incorporates multiple assisted reproductive technology cycles from the same woman as a surrogate for inherent fertility, offers a novel and complementary perspective for assessing interventions using national surveillance data.

Fatty acid supplementation into warming solutions improves pregnancy outcomes after single vitrified-warmed cleavage stage embryo transfers

Purpose

This study aimed to examine the embryonic development of human 4-cell stage embryos after warming with fatty acids (FAs) and to assess the pregnancy outcomes after single vitrified-warmed cleavage stage embryo transfers (SVCTs).

Methods

Experimental study: A total of 217 discarded, vitrified human 4-cell stage embryos donated for research by consenting couples were used. The embryos were warmed using the fatty acid (FA)-supplemented solutions (FA group) or nonsupplemented solutions (control group). The developmental rate, morphokinetics, and outgrowth competence were analyzed. Clinical study: The treatment records of women undergoing SVCT in natural cycles between April and September 2022 were retrospectively analyzed (April-June 2022, control group; July-September 2022, FA group).

Results

Experimental study: The rate of morphologically good blastocysts was significantly higher in the FA group than in the control group (p = 0.0302). The morphokinetics during cleavage, morula, and blastocyst stages were comparable between the groups. The outgrowth was significantly increased in the FA group (p = 0.0438). Clinical study: The rates of implantation, clinical pregnancy, and ongoing pregnancy after SVCTs were significantly increased in the FA group (p = 0.0223-0.0281).

Conclusions

Fatty acid-supplemented warming solutions effectively improve embryo development to the blastocyst stage and pregnancy outcomes after SVCTs.

Preimplantation genetic testing for aneuploidy: challenges in clinical practice

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

A SART data cost-effectiveness analysis of planned oocyte cryopreservation versus in vitro fertilization with preimplantation genetic testing for aneuploidy considering ideal family size

OBJECTIVE

To determine the cost-effectiveness of planned oocyte cryopreservation (OC) as a strategy for delayed childbearing to achieve 1 or 2 live births (LB) compared with in vitro fertilization (IVF) and preimplantation genetic testing for aneuploidy (PGT-A) at advanced reproductive age.

DESIGN

Decision tree model with sensitivity analyses using data from the Society for Assisted Reproductive Technology Clinical Outcome Reporting System and other clinical sources.

SETTING

Not applicable.

PATIENT(S)

A data-driven simulated cohort of patients desiring delayed childbearing with an ideal family size of 1 or 2 LB.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Probability of achieving ≥1 or 2 LB, average and maximum cost per patient, cost per percentage point increase in chance of LB, and population-level cost/LB.

RESULT(S)

For those desiring 1 LB, planned OC at age 33 with warming at age 43 decreased the average total cost per patient from $62,308 to $30,333 and increased the likelihood of LB from 50% to 73% when compared with no OC with up to 3 cycles of IVF/PGT-A at age 43. For those desiring 2 LB, 2 cycles of OC at age 33 and warming at age 40 yielded the lowest cost per patient and highest likelihood of achieving 2 LB ($51,250 and 77%, respectively) when compared withpursuing only 1 cycle of OC ($75,373 and 61%, respectively), no OC and IVF/PGT-A with embryo banking ($79,728 and 48%, respectively), or no OC and IVF/PGT-A without embryo banking ($79,057 and 19%, respectively). Sensitivity analyses showed that OC remained cost-effective across a wide range of ages at cryopreservation. For 1 LB, OC achieved the highest likelihood of success when pursued before age 32 and remained more effective than IVF/PGT-A when pursued before age 39, and for 2 LB, 2 cycles of OC achieved the highest likelihood of success when pursued before age 31 and remained more effective than IVF/PGT-A when pursued before age 39.

CONCLUSION(S)

Among patients planning to postpone childbearing, OC is cost-effective and increases the odds of achieving 1 or 2 LB when compared with IVF/PGT-A at a more advanced reproductive age.

A novel multifunctional haplotyping-based preimplantation genetic testing for different genetic conditions

STUDY QUESTION

Is there an efficient and cost-effective detection platform for different genetic conditions about embryos?

SUMMARY ANSWER

A multifunctional haplotyping-based preimplantation genetic testing platform was provided for detecting different genetic conditions.

WHAT IS KNOWN ALREADY

Genetic disease and chromosomal rearrangement have been known to significantly impact fertility and development. Therefore, preimplantation genetic testing for aneuploidy (PGT-A), monogenic disorders (PGT-M) and structural rearrangements (PGT-SR), a part of ART, has been presented together to minimize the fetal genetic risk and increase pregnancy rate. For patients or their families who are suffering from chromosome abnormality, monogenic disease, unexplained repeated spontaneous abortion or implantation failure, after accepting genetic counseling, they may be suggested to accept detection from more than one PGT platforms about the embryos to avoid some genetic diseases. However, PGT platforms work through different workflows. The high costliness, lack of material and long-time operation of combined PGT platforms limit their application.

STUDY DESIGN, SIZE, DURATION

All 188 embryonic samples from 43 families were tested with HaploPGT platform, and most of their genetic abnormalities had been determined by different conventional PGT methods beforehand. Among them, there were 12 families only carrying structural rearrangements (115 embryos) in which 9 families accepted implantation and 5 families had normal labor ART outcomes, 7 families only carrying monogenic diseases (26 embryos) and 3 families carrying both structural rearrangements and monogenic diseases (26 embryos). Twelve monopronucleated zygotes (1PN) samples and 9 suspected triploid samples were collected from 21 families.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Here, we raised a comprehensive PGT method called HaploPGT, combining reduced representation genome sequencing, read-count analysis, B allele frequency and haplotyping analysis, to simultaneously detect different genetic disorders in one single test.

MAIN RESULTS AND THE ROLE OF CHANCE

With 80 million reads (80M) genomic data, the proportion of windows (1 million base pairs (Mb)) containing two or more informative single nucleotide polymorphism (SNP) sites was 97.81%, meanwhile the genotyping error rate stabilized at a low level (2.19%). Furthermore, the informative SNPs were equally distributed across the genome, and whole-genomic haplotyping was established. Therefore, 80M was chosen to balance the cost and accuracy in HaploPGT. HaploPGT was able to identify abnormal embryos with triploid, global and partial loss of heterozygosity, and even to distinguish parental origin of copy number variation in mosaic and non-mosaic embryos. Besides, by retrospectively analyzing 188 embryonic samples from 43 families, HaploPGT revealed 100% concordance with the available results obtained from reference methods, including PGT-A, PGT-M, PGT-SR and PGT-HLA.

LIMITATIONS, REASON FOR CAUTION

Despite the numerous benefits HaploPGT could bring, it still required additional family members to deduce the parental haplotype for identifying balanced translocation and monogenic mutation in tested embryos. In terms of PGT-SR, the additional family member could be a reference embryo with unbalanced translocation. For PGT-M, a proband was normally required. In both cases, genomic information from grandparents or parental siblings might help for haplotyping theoretically. Another restriction was that haploid, and diploid resulting from the duplication of a haploid, could not be told apart by HaploPGT, but it was able to recognize partial loss of heterozygosity in the embryonic genome. In addition, it should be noted that the location of rearrangement breakpoints and the situation of mutation sites were complicated, which meant that partial genetic disorders might not be completely detected.

WIDER IMPLICATIONS OF THE FINDINGS

HaploPGT is an efficient and cost-effective detection platform with high clinical value for detecting genetic status. This platform could promote the application of PGT in ART, to increase pregnancy rate and decrease the birth of children with genetic diseases.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the National Natural Science Foundation of China (81873478, to L.H.), National Key R&D Program of China (2018YFC1003100, to L.H.), the Natural Science Foundation of Hunan Province (Grant 2022JJ30414, to P.X.), Hunan Provincial Grant for Innovative Province Construction (2019SK4012) and the Scientific Research Foundation of Reproductive and Genetic Hospital of China International Trust & Investment Corporation (CITIC)-Xiangya (YNXM-201910). Haplotyping analysis has been licensed to Basecare Co., Ltd. L.K., Y.M., K.K., D.Z., N.L., J.Z. and R.D. are Basecare Co., Ltd employees. The other authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

To mask or not to mask mosaicism? The impact of reporting embryo mosaicism on reproductive potential

PURPOSE

To evaluate euploidy rates and probability of having at least one euploid embryo for transfer per cycle when mosaicism is reported compared to when it is masked.

METHODS

Women age 18-46 years who underwent PGT-A with next generation sequencing of blastocyst biopsies were analyzed. When reported, mosaic embryos were classified as low-level, 20-40% mosaic, or high-level, 41-80% mosaic. When masked, low-level mosaics were categorized as euploid and high-level mosaics were considered aneuploid. Comparative analyses were performed with χ2 tests and t-tests.

RESULTS

A total of 22,504 PGT-A biopsy cycles from 18,401 patients were included. These cycles were from 293 different clinics with a mean of 1.22 cycles per patient. The majority of cycles (94.8%) reported mosaicism, and only 5.2% cycles were masked. The euploidy rate was significantly lower when mosaicism was reported versus masked (38.7% v 47.4%, p < 0.0001), which remained significant for age 40 years old and younger. The mosaic reporting cohort was less likely to have at least one euploid embryo for transfer (68.8%) compared to the masked cohort (75.7%) (p < 0.0001); however, this was no longer significant after stratification by age.

CONCLUSION

Mosaicism reporting shows an overall expected reduction in euploidy rate. In turn, the probability of having a euploid embryo to transfer depends on clinic transfer practices and patient preference. If mosaic embryos are not transferred, we observe a reduction in probability of having an embryo for transfer. Although the magnitude of these differences is small, our data show that mosaic reporting may contribute to embryo attrition rate.

Embryologist agreement when assessing blastocyst implantation probability: is data-driven prediction the solution to embryo assessment subjectivity?

STUDY QUESTION

What is the accuracy and agreement of embryologists when assessing the implantation probability of blastocysts using time-lapse imaging (TLI), and can it be improved with a data-driven algorithm?

SUMMARY ANSWER

The overall interobserver agreement of a large panel of embryologists was moderate and prediction accuracy was modest, while the purpose-built artificial intelligence model generally resulted in higher performance metrics.

WHAT IS KNOWN ALREADY

Previous studies have demonstrated significant interobserver variability amongst embryologists when assessing embryo quality. However, data concerning embryologists' ability to predict implantation probability using TLI is still lacking. Emerging technologies based on data-driven tools have shown great promise for improving embryo selection and predicting clinical outcomes.

STUDY DESIGN, SIZE, DURATION

TLI video files of 136 embryos with known implantation data were retrospectively collected from two clinical sites between 2018 and 2019 for the performance assessment of 36 embryologists and comparison with a deep neural network (DNN).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We recruited 39 embryologists from 13 different countries. All participants were blinded to clinical outcomes. A total of 136 TLI videos of embryos that reached the blastocyst stage were used for this experiment. Each embryo's likelihood of successfully implanting was assessed by 36 embryologists, providing implantation probability grades (IPGs) from 1 to 5, where 1 indicates a very low likelihood of implantation and 5 indicates a very high likelihood. Subsequently, three embryologists with over 5 years of experience provided Gardner scores. All 136 blastocysts were categorized into three quality groups based on their Gardner scores. Embryologist predictions were then converted into predictions of implantation (IPG ≥ 3) and no implantation (IPG ≤ 2). Embryologists' performance and agreement were assessed using Fleiss kappa coefficient. A 10-fold cross-validation DNN was developed to provide IPGs for TLI video files. The model's performance was compared to that of the embryologists.

MAIN RESULTS AND THE ROLE OF CHANCE

Logistic regression was employed for the following confounding variables: country of residence, academic level, embryo scoring system, log years of experience and experience using TLI. None were found to have a statistically significant impact on embryologist performance at α = 0.05. The average implantation prediction accuracy for the embryologists was 51.9% for all embryos (N = 136). The average accuracy of the embryologists when assessing top quality and poor quality embryos (according to the Gardner score categorizations) was 57.5% and 57.4%, respectively, and 44.6% for fair quality embryos. Overall interobserver agreement was moderate (κ = 0.56, N = 136). The best agreement was achieved in the poor + top quality group (κ = 0.65, N = 77), while the agreement in the fair quality group was lower (κ = 0.25, N = 59). The DNN showed an overall accuracy rate of 62.5%, with accuracies of 62.2%, 61% and 65.6% for the poor, fair and top quality groups, respectively. The AUC for the DNN was higher than that of the embryologists overall (0.70 DNN vs 0.61 embryologists) as well as in all of the Gardner groups (DNN vs embryologists-Poor: 0.69 vs 0.62; Fair: 0.67 vs 0.53; Top: 0.77 vs 0.54).

LIMITATIONS, REASONS FOR CAUTION

Blastocyst assessment was performed using video files acquired from time-lapse incubators, where each video contained data from a single focal plane. Clinical data regarding the underlying cause of infertility and endometrial thickness before the transfer was not available, yet may explain implantation failure and lower accuracy of IPGs. Implantation was defined as the presence of a gestational sac, whereas the detection of fetal heartbeat is a more robust marker of embryo viability. The raw data were anonymized to the extent that it was not possible to quantify the number of unique patients and cycles included in the study, potentially masking the effect of bias from a limited patient pool. Furthermore, the lack of demographic data makes it difficult to draw conclusions on how representative the dataset was of the wider population. Finally, embryologists were required to assess the implantation potential, not embryo quality. Although this is not the traditional approach to embryo evaluation, morphology/morphokinetics as a means of assessing embryo quality is believed to be strongly correlated with viability and, for some methods, implantation potential.

WIDER IMPLICATIONS OF THE FINDINGS

Embryo selection is a key element in IVF success and continues to be a challenge. Improving the predictive ability could assist in optimizing implantation success rates and other clinical outcomes and could minimize the financial and emotional burden on the patient. This study demonstrates moderate agreement rates between embryologists, likely due to the subjective nature of embryo assessment. In particular, we found that average embryologist accuracy and agreement were significantly lower for fair quality embryos when compared with that for top and poor quality embryos. Using data-driven algorithms as an assistive tool may help IVF professionals increase success rates and promote much needed standardization in the IVF clinic. Our results indicate a need for further research regarding technological advancement in this field.

STUDY FUNDING/COMPETING INTEREST(S)

Embryonics Ltd is an Israel-based company. Funding for the study was partially provided by the Israeli Innovation Authority, grant #74556.

TRIAL REGISTRATION NUMBER

N/A.

Impact of in vitro fertilization state mandates for third party insurance coverage in the United States: a review and critical assessment

The American Society for Reproductive Medicine estimates that fewer than a quarter of infertile couples have sufficient access to infertility care. Insurers in the United States (US) have long considered infertility to be a socially constructed condition, and thus in-vitro fertilization (IVF) an elective intervention. As a result, IVF is cost prohibitive for many patients in the US. State infertility insurance mandates are a crucial mechanism for expanding access to fertility care in the US in the absence of federal legislation. The first state insurance mandate for third party coverage of infertility services was passed by West Virginia in 1977, and Maryland passed the country's first IVF mandate in 1985. To date, twenty states have passed legislation requiring insurers to cover or offer coverage for the diagnosis and treatment of infertility. Ten states currently have "comprehensive" IVF mandates, meaning they require third party coverage for IVF with minimal restrictions to patient eligibility, exemptions, and lifetime limits. Several studies analyzing the impact of infertility and IVF mandates have been published in the past 20 years. In this review, we characterize and contextualize the existing evidence of the impact of state insurance mandates on access to infertility treatment, IVF practice patterns, and reproductive outcomes. Furthermore, we summarize the arguments in favor of insurance coverage for infertility care and assess the limitations of state insurance mandates as a strategy for increasing access to infertility treatment. State mandates play a key role in the promotion of evidence-based practices and represent an essential and impactful strategy for the advancement of gender equality and reproductive rights.

Polygenic embryo screening: four clinical considerations warrant further attention

Recent advances in developing polygenic scores have made it possible to screen embryos for common, complex conditions and traits. Polygenic embryo screening (PES) is currently offered commercially, and though there has been much recent media and academic coverage, reproductive specialists' points of view have not yet been prominent in these discussions. We convened a roundtable of multidisciplinary experts, including reproductive specialists to discuss PES and its implications. In this Opinion, we describe four clinically relevant issues associated with the use of PES that have not yet been discussed in the literature and warrant consideration.