Faculty Bibliography

OBJECTIVE:To understand the clinical risks associated with the transfer of embryos classified as a mosaic using preimplantation genetic testing for aneuploidy. DESIGN:Analysis of data collected between 2017 and 2023. SETTING:Multicenter. PATIENTS:Patients of infertility treatment. INTERVENTION:Comparison of pregnancies resulting from embryos classified as euploid or mosaic using the 20%-80% interval in chromosomal intermediate copy numbers to define a mosaic result. MAIN OUTCOME MEASURES:Rates of spontaneous abortion, birth weight, length of gestation, incidence of birth defects, and chromosomal status during gestation. RESULTS:Implanted euploid embryos had a significantly lower risk of spontaneous abortion compared with mosaic embryos (8.9% [n = 8,672; 95% confidence interval {CI95} 8.3, 9.5] vs. 22.2% [n = 914; CI95 19.6, 25.0]). Embryos with mosaicism affecting whole chromosomes (not segmental) had the highest risk of spontaneous abortion (27.6% [n = 395; CI95 23.2, 32.3]). Infants born from euploid, mosaic, and whole chromosome mosaic embryos had average birth weights and lengths of gestation that were not statistically different (3,118 g and 267 days [n = 488; CI95 3,067, 3,169, and 266, 268], 3052 g and 265 days [n = 488; CI95 2,993, 3,112, and 264,267], 3,159 g and 268 days [n = 194; CI95 3,070, 3,249, and 266,270], respectively). Out of 488 infants from mosaic embryo transfers (ETs), one had overt gross abnormalities as defined by the Centers for Disease Control and Prevention. Most prenatal tests performed on pregnancies from mosaic ETs had normal results, and only three pregnancies produced prenatal test results reflecting the mosaicism detected at the embryonic stage (3 out of 250, 1.2%; CI95 0.25, 3.5). CONCLUSION:Although embryos classified as mosaic experience higher rates of miscarriage than euploid embryos (with a particularly high frequency shortly after implantation), infants born of mosaic ETs are similar to infants of euploid ETs. Prenatal testing indicates that mosaicism resolves during most pregnancies, although this process is not perfectly efficient. In a small percentage of cases, the mosaicism persists through gestation. These findings can serve as risk-benefit considerations for mosaic ETs in the fertility clinic.

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.

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 LH ≥ 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 (p = 0.14), maturity rate (p = 0.40) or fertilization rates (p = 0.49) based on LH response. There was no difference in LH response based on use of combination vs. GnRHa alone trigger (p = 0.21) or GnRHa trigger dose (p = 0.46). The EIC-LH was more predictive of LH trigger response than B-FSH (p < 0.005).The optimal B-FSH and EIC-LH values to yield an optimal LH response was ≥ 5.5 mIU/mL and ≥ 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.

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.

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.
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Objective: The use of GnRH-a trigger in antagonist controlled ovarian hyperstimulation (COH) cycles has increased due to its enhanced safety profile. However, response, as measured by the serum LH level post trigger, vary considerably^1-6. We investigated the impact of serum LH response to GnRH-a trigger in antagonist COH cycles on oocyte yield, oocyte maturity, blastocyst formation, PGT-A and pregnancy outcomes.
Material(s) and Method(s): This is a retrospective cohort study in a single university-based fertility center of all GnRH-antagonist COH cycles utilizing GnRH-a alone or in combination with 1000u of human chorionic gonadotropin (hCG) for trigger from 2017 to 2020. An optimal response to GnRH-a trigger was defined as LH >= 40 mIU/mL and suboptimal response was defined as LH < 40 mIU/mL on the morning after trigger. Subanalyses with responses of LH >= 15 mIU/mL and LH < 15 mIU/mL were also performed. Primary outcomes included oocyte yield, oocyte maturity rate, blastocyst formation rate, euploidy rate, aneuploidy rate and simple mosaic rate. Secondary outcomes included biochemical pregnancy rate (BPR), spontaneous abortion rate (SABR) and ongoing/pregnancy live birth rate (OP/LBR). Primary and secondary outcomes were also stratified by age, race and BMI. Descriptive statistics (median +/- range for continuous variables), Mann Whitey U and Fisher's Exact tests were performed accordingly with p<0.05 defined as significant.
Result(s): This study included 3,833 retrieval cycles with 1,435 single thawed euploid embryo transfers (STEET) among 2,618 patients. Ten percent (351/3446) of retrieval cycles had suboptimal and 90% (3446/3833) had optimal response to GnRH-a trigger. There was no difference in median oocyte yield (16 vs 17 oocytes per cycle, p=0.92), or oocyte maturity (77% vs 76%, p=0.43), fertilization (76% vs 77%, p=0.48) and blastocyst formation (51% vs 52%, p=0.88) rates by response. There were no significant differences in the rate of euploidy (35% vs 39%, p=0.55), aneuploidy (51% vs 47%, p=0.56) and simple mosaic (11% vs 11%, p=1) between groups. Seven percent (102/1435) of STEETs utilized embryos from a cycle with suboptimal response and 93% (1333/1435) from optimal response to GnRH trigger. There were no significant differences in BPR [19/44 (14%) vs 164/1907 (9%), p=0.2], SABR [11/144 (8%) vs 152/1907 (8%), p=1] and OP/LBR [85/144 (59%) vs 1127/1907 (59%), p=1]. No differences in pregnancy outcomes were found in the subanalyses of LH >= and < 15 mIU/mL and when data were stratified by SART age ranges, race and BMI.
Conclusion(s): A suboptimal response to GnRH-a trigger (LH < 40) is not associated with lower oocyte yield, oocyte maturity rate, blastocyst rate, euploidy rate or worse pregnancy outcomes compared to an optimal response (LH >= 40). Additional studies with larger cohorts are needed to further investigate these findings and with different thresholds of response. Impact Statement: A suboptimal LH response to GnRH-a trigger may not predict poor cycle outcomes. Providers should not hesitate to use GnRH-a trigger, especially in patients with identifiable risk factors for ovarian hyperstimulation syndrome (OHSS)⁷. Support: None.
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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.
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Objective: E2P is a technique for IVF protocols in poor responders to reduce cycle cancelation due to elevated FSH as well as increase stimulation response. Yet data is inconsistent on the impact on clinical pregnancy rates.¹ We sought to evaluate if E2P increases euploidy rates in IVF with PGTA.
Material(s) and Method(s): This is a retrospective cohort study of IVF cycles with PGTA from 3/2020-12/2021 at a single academic fertility center. E2P cycles were compared to age and AMH matched controls (CON) (1:2 ratio). The primary outcome was number of euploid embryos. Secondary outcomes were cycle start follicle stimulation hormone level (FSH), total gonadotrophin (GND) dose, number oocytes, mature oocytes (MII), fertilization rate (2PN), and number of embryos biopsied (BX). Mann Whitney and Chi-square tests were performed (p<0.05 significant). Data is reported in median (range) and percentages.
Result(s): 337 E2P cycles were compared to 674 CON. There were fewer microdose lupron (MCD) cycles in E2P patients (E2P: 88% antagonist (ANT), 12% MCD vs CON: 76% ANT, 24% MCD, p<0.01). Similar cancelation rates [E2P: 14% (47/337) vs CON: 12% (82/674), p=0.42] and poor blast formation (defined as nothing for biopsy) [E2P: 18% (60/337) vs CON: 15% (103/674), p=0.24] were seen between groups. Number of euploid embryos were similar across all SART age groups except for 38-40 years (y), with fewer euploids in E2P (Table). Cycle start FSH was lower and total GND dose was higher for E2P (p<0.05). Other cycle outcomes were not different.
Conclusion(s): E2P is a viable tool for PGTA freeze all cycles, but does not improve euploidy rate; larger studies are necessary to determine if E2P produces fewer euploids in >38y. Impact Statement: E2P cycles require higher GND dose without increased yield in euploid embryos. [Formula presented] Support: None REFERENCES: 1. Orvieto R. Pretreatment: Does it improve quantity or quality? Fertil Steril. 2022 Apr;117(4):657-663. Epub 2022 Mar 5. PMID:.
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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.
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