Blinded rebiopsy and analysis of non-euploid embryos with two distinct preimplantation genetic testing platforms for aneuploidy
OBJECTIVE:To determine how often a non-euploid result from a single trophectoderm biopsy tested with next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) is concordant with rebiopsies tested with a single nucleotide polymorphism (SNP) array-based PGT-A platform. DESIGN/METHODS:Blinded prospective cohort study. SETTING/METHODS:University-affiliated fertility center. PATIENT(S)/METHODS:100 blastocysts were chosen from donated samples; on trophectoderm biopsy with NGS-based PGT-A, 40 had at least one whole chromosome full copy number aneuploidy alone, 20 had a single whole chromosome intermediate copy number ("whole chromosome mosaic"), 20 had a single full segmental aneuploidy, and 20 had a single segmental intermediate copy number ("segmental mosaic"). INTERVENTIONS/METHODS:Four rebiopsies were collected from each embryo: three trophectoderm biopsies and the remaining embryo. Each rebiopsy was randomized, blinded, and assessed with a SNP array-based PGT-A platform that combines copy number and allele ratio analyses, without mosaicism reporting. MAIN OUTCOME MEASURE(S)/METHODS:Concordance: 1) between the NGS result and rebiopsy results, and 2) within each embryo's blinded rebiopsy results. RESULT(S)/RESULTS:NGS-diagnosed whole chromosome aneuploidy was reconfirmed in 95% (95% confidence interval [CI] 83-99%) of embryos; two embryos with NGS-diagnosed whole chromosome aneuploidy were called euploid on all conclusive rebiopsies. Among embryos with NGS-diagnosed whole chromosome mosaicism, 35% (95% CI 15-59%) were called euploid and 15% (95% CI 3-38%) were called whole chromosome aneuploid on all conclusive rebiopsies. 30% (95% CI 12-54%) of embryos with NGS-diagnosed segmental aneuploidy and 65% (95% CI 41-85%) of embryos with NGS-diagnosed segmental mosaicism were called euploid on all conclusive rebiopsies. In total, 13% (95% CI 6-25%) of embryos with NGS-diagnosed full copy number aneuploidy and 50% (95% CI 34-66%) of embryos with NGS-diagnosed mosaicism had uniformly euploid SNP results. Conversely, all embryos with at least one non-euploid SNP result (n=72) either had: 1) SNP-diagnosed aneuploidy on another rebiopsy from the same embryo, or 2) NGS-diagnosed aneuploidy/mosaicism involving the same chromosome. CONCLUSION(S)/CONCLUSIONS:NGS-diagnosed whole chromosome aneuploidy is highly concordant with rebiopsies tested with SNP array-based PGT-A; however, whole chromosome mosaicism, segmental aneuploidy, and segmental mosaicism are less concordant, reinforcing that embryos with these results may have reproductive potential and be suitable for transfer.
The Landscape of Telomere Length and Telomerase in Human Embryos at Blastocyst Stage
The telomere length of human blastocysts exceeds that of oocytes and telomerase activity increases after zygotic activation, peaking at the blastocyst stage. Yet, it is unknown whether aneuploid human embryos at the blastocyst stage exhibit a different profile of telomere length, telomerase gene expression, and telomerase activity compared to euploid embryos. In present study, 154 cryopreserved human blastocysts, donated by consenting patients, were thawed and assayed for telomere length, telomerase gene expression, and telomerase activity using real-time PCR (qPCR) and immunofluorescence (IF) staining. Aneuploid blastocysts showed longer telomeres, higher telomerase reverse transcriptase (TERT) mRNA expression, and lower telomerase activity compared to euploid blastocysts. The TERT protein was found in all tested embryos via IF staining with anti-hTERT antibody, regardless of ploidy status. Moreover, telomere length or telomerase gene expression did not differ in aneuploid blastocysts between chromosomal gain or loss. Our data demonstrate that telomerase is activated and telomeres are maintained in all human blastocyst stage embryos. The robust telomerase gene expression and telomere maintenance, even in aneuploid human blastocysts, may explain why extended in vitro culture alone is insufficient to cull out aneuploid embryos during in vitro fertilization.
Serum Gonadotropin Levels Predict Post-Trigger Luteinizing Hormone Response in Antagonist Controlled Ovarian Hyperstimulation Cycles
The objective of this study was to investigate the utility of using serum gonadotropin levels to predict optimal luteinizing hormone (LH) response to gonadotropin releasing hormone agonist (GnRHa) trigger. A retrospective cohort study was performed of all GnRH-antagonist controlled ovarian hyperstimulation (COH) cycles at an academic fertility center from 2017-2020. Cycles that utilized GnRHa alone or in combination with human chorionic gonadotropin (hCG) for trigger were included. Patient and cycle characteristics were collected from the electronic medical record. Optimal LH response was defined as a serum LHâ€‰â‰¥â€‰40 mIU/mL on the morning after trigger. Total sample size was 3865 antagonist COH cycles, of which 91% had an optimal response to GnRHa trigger. Baseline FSH (B-FSH) and earliest in-cycle LH (EIC-LH) were significantly higher in those with optimal response. Multivariable logistic regression affirmed association of optimal response with EIC-LH, total gonadotropin dosage, age, BMI and Asian race. There was no difference in the number of oocytes retrieved (pâ€‰=â€‰0.14), maturity rate (pâ€‰=â€‰0.40) or fertilization rates (pâ€‰=â€‰0.49) based on LH response. There was no difference in LH response based on use of combination vs. GnRHa alone trigger (pâ€‰=â€‰0.21) or GnRHa trigger dose (pâ€‰=â€‰0.46). The EIC-LH was more predictive of LH trigger response than B-FSH (pâ€‰<â€‰0.005).The optimal B-FSH and EIC-LH values to yield an optimal LH response wasâ€‰â‰¥â€‰5.5 mIU/mL andâ€‰â‰¥â€‰1.62 mIU/mL, respectively. In an era of personalized medicine, utilizing cycle and patient characteristics, such as early gonadotropin levels, may improve cycle outcomes and provide further individualized care.
Utilization of standardized preimplantation genetic testing for aneuploidy (PGT-A) via artificial intelligence (AI) technology is correlated with improved pregnancy outcomes in single thawed euploid embryo transfer (STEET) cycles
PURPOSE/OBJECTIVE:To investigate the role of standardized preimplantation genetic testing for aneuploidy (PGT-A) using artificial intelligence (AI) in patients undergoing single thawed euploid embryo transfer (STEET) cycles. METHODS:Technology Platform, AI 1.0). The second group included embryos analyzed by AI 1.0 and SNP analysis (PGTai2.0, AI 2.0). Primary outcomes included rates of euploidy, aneuploidy and simple mosaicism. Secondary outcomes included rates of implantation (IR), clinical pregnancy (CPR), biochemical pregnancy (BPR), spontaneous abortion (SABR) and ongoing pregnancy and/or live birth (OP/LBR). RESULTS:A total of 24,908 embryos were analyzed, and classification rates using AI platforms were compared to subjective NGS. Overall, those tested via AI 1.0 showed a significantly increased euploidy rate (36.6% vs. 28.9%), decreased simple mosaicism rate (11.3% vs. 14.0%) and decreased aneuploidy rate (52.1% vs. 57.0%). Overall, those tested via AI 2.0 showed a significantly increased euploidy rate (35.0% vs. 28.9%) and decreased simple mosaicism rate (10.1% vs. 14.0%). Aneuploidy rate was insignificantly decreased when comparing AI 2.0 to NGS (54.8% vs. 57.0%). A total of 1,174 euploid embryos were transferred. The OP/LBR was significantly higher in the AI 2.0 group (70.3% vs. 61.7%). The BPR was significantly lower in the AI 2.0 group (4.6% vs. 11.8%). CONCLUSION/CONCLUSIONS:Standardized PGT-A via AI significantly increases euploidy classification rates and OP/LBR, and decreases BPR when compared to standard NGS.
Fifteen Years of Autologous Oocyte Thaw Outcomes From a Large University-Based Fertility Center
FRAGILE X CARRIERS: IS THERE EXPANSION IN UTILIZATION OF PREIMPLANTATION GENETIC TESTING FOR MONOGENIC DISORDERS (PGT-M)? [Meeting Abstract]
Objective: Fragile X (FgX) is a recommended part of carrier screening with pre- and full mutations associated with a spectrum of disease including intellectual disability, tremor ataxia syndrome and premature ovarian insufficiency. Risk of expansion is categorized based on number of CGG repeats.1 Testing for AGG interruptions can offer further risk assessment in some cases.1 As these tests become more commonplace, our objective was to determine how often screened patients select PGT-M for FgX.
Material(s) and Method(s): This is a retrospective case series at a single academic fertility center. Electronic medical records were queried to identify patients with a positive carrier screen for FgX from 2008-2022 and those undergoing PGT-M for FgX. Assisted reproductive treatments and outcomes were reviewed. Kruskal Wallis and Chi-square statistical tests were performed (p<0.05 significant).
Result(s): 393 positive FgX reports were identified including 20 prospective oocyte donors. 63% (247/393) had an intermediate (INT) number of CGG repeats (45-54), 34% (133/393) had a premutation (PRE) (55-200 repeats) and 0.8% (3/393) had a full mutation (FUL) (>200 repeats). 61% (238/393) underwent fertility treatment at our center. PRE patients were younger (INT: 36 (17-47) vs PRE: 33 (21-44) vs FUL: 37 (37-39) years (Y), p<0.01). Anti-mullerian hormone levels were similar (INT: 1.9 (0.03-14) vs PRE: 1.5 (0.01-8.7) vs FUL: 3 (0.1-5) ng/mL, p=0.08). Only 37% (49/133) of PRE carriers underwent AGG testing to further risk stratify expansion potential, as did 2% (4/247) of INT. 25% (13/53) had 0 AGGs: 4 declined fertility treatment, 4 cryopreserved oocytes, 5 underwent PGT-M. 12% (49/393) in total underwent PGT-M: 4% INT (2/49), 73% PRE (36/49), 6% FUL (3/49). 27% (13/49) of PGT-M patients underwent AGG testing: 38% (5/13) had 0 AGG, 38% (5/13) had 1 AGG, and 23% (3/13) had 2 AGGs. 8% (4/49) additional patients were offered but declined AGG testing. 18% (9/49) of PGT-M patients had terminated an affected pregnancy prior to PGT-M. 10% (5/49) had documented family members affected or PRE carriers. Patients underwent median 2 retrieval cycles (range 0-5) and 1 embryo transfer cycle (range 0-5). 31% (14/45) of patients with completed treatment did not achieved an autologous euploid unaffected embryo for transfer; two of these patients transferred non-euploid unaffected embryos and 71% (10/14) had AMH <0.8ng/mL. 1 INT and 2 PRE female embryos were also transferred. 46% (13/28) of transfers resulted in a live birth.
Conclusion(s): PGT-M is most commonly used for PRE carriers and with a history of prior affected pregnancy or family member, with varied use of AGG testing. Patients with low ovarian reserve are less likely to achieve an autologous live birth of an unaffected embryo from PGT-M. Impact Statement: FgX premutation carriers do not have uniform uptake of AGG testing or PGT-M and require individualized counseling due to differences in risk assessment and varied assisted reproductive technology outcomes. Support: None REFERENCES:: 1. Monaghan KG, Lyon E, Spector EB; American College of Medical Genetics and Genomics. ACMG Standards and Guidelines for fragile X testing: a revision to the disease-specific supplements to the Standards and Guidelines for Clinical Genetics Laboratories of the American College of Medical Genetics and Genomics. Genet Med. 2013 Jul;15(7):575-86.
SPECTRUM OF EMBRYO MOSAICISM DETECTED BY PREIMPLANTATION GENETIC TESTING FOR ANEUPLOIDY (PGT-A) DETERMINES REPRODUCTIVE OUTCOME [Meeting Abstract]
Objective: Historically, PGT-A results were applied in a binary fashion: embryos categorized as normal were transferred, and those categorized as abnormal were not. While embryos with euploid results have consistent reproductive outcomes, it has now become evident that "abnormal" results can be subcategorized, depending on whether an intermediate copy number is observed ("mosaic"), range of intermediate copy number (estimated percentage of biopsied cells with the abnormality), and type of abnormality (segmental or full monosomy/trisomy).
Material(s) and Method(s): Frozen embryo transfers at our clinic in which PGT-A was performed by next-generation sequencing (NGS) were reviewed. Biopsies from embryos transferred were categorized as either euploid (<20% undetectable abnormal cells), low level segmental mosaic (LL-SM; 20-40% abnormal), high level segmental mosaic (HL-SM; 40-80% abnormal), low level whole chromosome mosaic (LL-WCM), high level whole chromosome mosaic (HL-WCM), or aneuploid (80-100% abnormal). Primary outcomes were implantation rate (IR; defined as presence of gestational sac), ongoing pregnancy rate at 7 weeks gestation (OPR), and spontaneous abortion rate (SABR; defined as loss of gestational sac). Contingency Chi-square (X2; 6x2) analysis with post hoc (2x2)'s were used for comparisons.
Result(s): Table 1 lists the primary outcomes for each PGT-A category. For IR and OPR, euploid and LL-SM embryos were indistinguishable; however, HL-SM, LL-WCM, HL-WCM, and aneuploid embryos were significantly different (p<0.001). While the limited sample size of spontaneous abortions was too small to make accurate comparisons between all 6 groups, a significantly higher SABR was observed for non-euploid embryos (p<0.001). There were no cases in which a non-euploid PGT-A result was confirmed by amniocentesis or in the newborn. [Formula presented]
Conclusion(s): Embryos with euploid and LL-SM results have the highest chance of producing a viable pregnancy. Those with other types of mosaic results can produce viable pregnancies, but at lower rates, and aneuploid embryos are least likely to be viable. Therefore, a spectrum of PGT-A results can help to predict reproductive potential. These data can be used to guide patient counseling about embryo transfer after PGT-A. Impact Statement: The amount and type of mosaicism in embryos correlates with OPR and SABR. Trophectoderm biopsy with NGS is a powerful tool in predicting reproductive outcomes. Support: None
ICING ON THE CAKE: CAN OOCYTES "ON ICE" RESULT IN MORE THAN ONE LIVE BIRTH (LB)? [Meeting Abstract]
Objective: Data regarding the chance of more than one LB from oocyte cryopreservation (OC) is lacking. We reviewed outcomes from patients (pts) with >=1 LB from thawed autologous oocytes (AOs) to examine: 1) how many have inventory (AOs or resultant euploid/untested/no result embryos), and 2) embryo transfer (ET) outcomes after 1st LB.
Material(s) and Method(s): We reviewed all pts who thawed AOs at our center in 2006-2021 and had >=1 resultant LB. Pts were excluded if OC was performed for a medical reason, as research, due to lack of sperm or a natural disaster, with embryo banking or for gestational carrier use.
Result(s): 191 pts had >=1 LB (median # OC cycles 1, median age at 1st OC 37 years (y), median # cryopreserved AOs 18, median # AOs thawed before 1st LB 15). After LB, 61% of pts (n=117) had inventory and 39% (n=74) did not; see table. Among pts with inventory, 12% (n=14) discarded or donated, 3% (n=4) transported out and 10% (n=12) consumed all inventory as of 1/2022. 22% of pts with inventory (n=26) had >=1 ET after LB. Among these pts, 21 thawed embryos (median # thawed 1, range 1-2), 4 thawed AOs (median # thawed 11, range 5-40) and 1 thawed both AOs + embryos (15 AOs + 4 embryos). Median time from the ET that led to 1st LB and next ET was 26 months (range 15-57) and median age at next ET was 44y (range 37-53). This ET resulted in: implantation rate of 63% (19/30), spontaneous abortion rate of 16% (3/19) and ongoing pregnancy (OP) + LB rate of 58% (15/26); 1 pregnancy was terminated for monozygotic twins. Among pts who had a LB from this ET, 66% (10/15) had remaining inventory and 33% (5/15) did not. Among pts who did not have a LB from this ET, 45% (5/11) had remaining inventory and 54% (6/11) did not; 5 of these unsuccessful pts returned for another ET and 2 had a LB. In total, 16 pts had 2 ETs result in OP/LB and 1 pt had 3 ETs result in LB. 10 more pts had >=2 children from a single ET (9 twins, 1 triplet); thus, we report 27 pts with >=2 children from OC. Among pts with >=2 children, median # OC cycles was 1 (range 1-8), median age at 1st OC was 37y (range 34-41), median # cryopreserved AOs was 20 (range 5-102) and median # thawed AOs was 19 (range 5-58).
Conclusion(s): Most pts (61%) had inventory after their 1st LB from OC, and most pts (65%) who returned for ET after LB achieved another OP/LB. Further research must explore pts' thoughts regarding OC inventory after LB and its associated storage fees. Impact Statement: OC can help pts achieve their ideal family size, even if >1 child. [Formula presented] Support: None.
IMPACT OF DISCREPANT VARIANT CLASSIFICATION ON PREIMPLANTATION GENETIC TESTING FOR MONOGENIC CONDITIONS (PGT-M) [Meeting Abstract]
Objective: The use of sequencing-based genetic testing has resulted in increasingly complex results interpretation. In contrast to diagnostic testing, only variants believed to be pathogenic or likely pathogenic (LP) are reported in carrier screening, while variants believed to be benign, likely benign (LB), or of unknown clinical significance (VUS) are not typically reported by the testing laboratory. However, laboratories frequently disagree on variant classification, and classifications may also change over time, as more data is compiled. Therefore, the same patient may have different results depending on the laboratory used and time of results reporting. The objective of this study was to assess the impact of discrepant variant classifications on use of PGT-M.
Material(s) and Method(s): Known cases in which discrepant variant classification impacted PGT-M utilization were reviewed. Cases were selected due to complicated genetic counseling and perceived or stated burden to patients.
Result(s): Ten cases were identified in which discrepant variant classification complicated PGT-M decision-making. Nine cases were identified through carrier screening, and one involved both carrier screening and diagnostic testing. The condition involved was X-linked in six cases, and autosomal recessive in four cases. The variant in question was initially reported as LP in 6/10 cases, and as pathogenic in 4/10 cases by the carrier screening laboratory. In 8/10 cases, at least one other laboratory disagreed with the initial classification and instead classified the variant as VUS, LB, or benign. In one case, the laboratory informed about a reclassification of an LP variant to VUS upon further inquiry, and in the last case, the laboratory reported a variant as pathogenic while omitting essential details about reduced penetrance and mild/variable expressivity. In the majority of cases (6/10), learning about discrepant variant information altered patient decision making regarding use of PGT-M; however, only one patient elected not to continue with PGT-M. Four other patients continued with PGT-M but planned to consider variant-positive embryos for transfer if needed, and in the last case, the patient was undecided between PGT-M or selecting a new gamete donor.
Conclusion(s): Discrepancies in variant classification between testing laboratories can pose challenges for decision-making about the use of PGT-M, and may lead to unnecessary use of this technology. Genetic counseling and thorough variant review is essential prior to PGT-M initiation, to ensure that both patients and clinicians have all necessary and current data to make informed reproductive decisions. The need for carrier screening laboratories to contribute variant-specific information to publicly available databases and include thorough variant-specific annotations on test reports is paramount to improving patient care and reducing both emotional and financial burdens of this costly and complex treatment. Impact Statement: This study is the first to demonstrate the impact of discrepant variant classification between carrier screening laboratories on PGT-M use.
CUMULATIVE LIVE BIRTH RATES (CLBRS) FROM FROZEN AUTOLOGOUS OOCYTES (AOS): LARGEST COHORT OF PLANNED OOCYTE CRYOPRESERVATION (OC) THAWS FROM A SINGLE CENTER IN THE UNITED STATES [Meeting Abstract]
Objective: Planned OC is increasing; yet, there is a lack of thaw data to provide an accurate estimate of CLBR.1 We reviewed our AO thaws to determine CLBR by age and #AOs.
Material(s) and Method(s): We reviewed AO thaws at our academic center from 2004-2021. Inclusion criteria: 1) >=1 live birth (LB)/ongoing pregnancy (OP) >12 weeks, or 2) all AOs + embryos from OC consumed. Exclusion criteria: 1) OC for a medical reason, as research, due to lack of sperm or a natural disaster, combined with embryos or for gestational carrier use, or 2) AOs/embryos from OC transported out before a LB. Primary outcome was CLBR (LB + OP). Patients (pts) were stratified by age and #AOs or metaphase II oocytes (M2s) thawed. If pts had >=1 OC cycle, we calculated a weighted age: [SIGMA (#AOs thawed x age at OC)] / [#AOs thawed]. Statistics included multiple logistic regression (MLR), Fischer's exact test, and chi-squared test (p<0.05 significant).
Result(s): 548 pts (median age at OC 38y, range 28-45y; 151 weighted ages used) underwent 767 OC (location: 90% our center, 9% elsewhere, 2% both; method: 77% vitrification, 4% slow cooling, 19% both), 604 thaw and 465 transfer cycles. 40% (n=218) of pts had >=1 LB/OP, resulting in 221 babies + 30 OPs. See table for CLBRs. In pts of all ages and <38y, CLBR increased as #AO/M2s thawed increased from 0-10 to 11-20 to >20 (p<0.03). In pts 38-39y, CLBR was lower if 0-10 vs. 11-20 or >20 AOs were thawed (p<0.01), but was similar if 11-20 vs. >20 AOs (p=0.34) or M2s (p=0.13) were thawed. In pts >=40y, CLBR did not differ based on #AOs (p=0.81) or M2s thawed (p=0.17). For pts with any # or >20 AO/M2s thawed, CLBR was higher in pts <38y and 38-39y vs. pts >=40y (p<0.04). In a MLR model adjusting for effect of age on #AOs, age and age-independent #AOs were predictive of LB.
Conclusion(s): CLBR increases as more AO/M2s are thawed. OC at <38y has a CLBR of ~50%, a reasonable rate in younger pts at an ideal age for OC. Impact Statement: Pts who freeze >20 AOs at <38y can expect >=70% CLBR based on actual outcomes. This is the largest report to date of AO thaw outcomes from a single U.S. center. [Formula presented] REFERENCES:: 1 Practice Committee of the American Society for Reproductive Medicine. Evidence-based outcomes after oocyte cryopreservation for donor oocyte in vitro fertilization and planned oocyte cryopreservation: a guideline. Fertil Steril. 2021 Jul;116(1):36-47.