A pilot study to investigate the clinically predictive values of copy number variations detected by next-generation sequencing of cell-free deoxyribonucleic acid in spent culture media.

OBJECTIVE: To investigate the positive predictive value and false positive risk of copy number variations (CNV's) detected in cell free deoxyribonucleic acid (DNA) from spent culture media for nonviable or aneuploid embryos. DESIGN: Diagnostic/prognostic accuracy study. PATIENT(S): Patients aged 35 and younger with an indication for IVF-ICSI and elective single frozen embryo transfer at a single, private IVF center. INTERVENTION: Embryo selection was performed according to the conventional grading, blinded to noninvasive preimplantation genetic testing for aneuploidy (niPGT-A) results. After clinical outcomes were established, spent culture media samples were analyzed. MAIN OUTCOME MEASURES: Prognostic accuracy of CNVs according to niPGT-A results to predict nonviability or clinical aneuploidy. RESULTS: One hundred twenty patients completed the study. Interpretations of next-generation sequencing (NGS) profiles were as follows: 7.5% (n = 9) failed quality control; 62.5% (n = 75) no CNVs detected; and 30% (n = 36) abnormal copy number detected. Stratification of abnormal NGS profiles was as follows: 15% (n = 18) whole chromosome and 15% (n = 18) uncertain reproductive potential. An intermediate CNV was evident in 27.8% (n = 5) of the whole chromosome abnormalities. The negative predictive value for samples with no detected abnormality was 57.3% (43/75). Whole chromosome abnormality was associated with a positive predictive value of 94.4% (17/18), lower sustained implantation rate (5.6%, 1/18), and higher relative risk (RR) for nonviability compared with no detected abnormalities (RR 2.21, 95% CI: 1.66-2.94). No other CNVs were associated with significant differences in the sustained implantation or RRs for nonviability. Unequal sex chromosome proportions suggested that maternal contamination was not uncommon. A secondary descriptive analysis of 705 supernumerary embryos revealed proportions of NGS profile interpretations similar to the transferred cohort. Significant median absolute pairwise differences between certain subcategories of CNV abnormalities were apparent. CONCLUSION: Whole chromosome abnormalities were associated with a high positive predictive value and significant RR for nonviability. Embryos associated with other CNVs had sustained implantation rates similar to those with no abnormalities detected. Further studies are required to validate the clinical applicability of niPGT-A. CLINICAL TRIAL REGISTRATION NUMBER: clinicaltrials.gov (NCT04732013).

Comprehensive chromosome screening of polar bodies and blastocysts from couples experiencing repeated implantation failure.

OBJECTIVE: To identify and transfer cytogenetically normal embryos after screening all chromosomes of first and second polar bodies (PBs) or trophectoderm samples with the use of comparative genomic hybridization. DESIGN: Clinical research study. SETTING: In vitro fertilization clinic referring samples to a specialist preimplantation genetic diagnosis laboratory. PATIENT(S): Thirty-two couples with repeated implantation failure. INTERVENTION(S): Zygotes from patients with repeated implantation failure and poor response to ovarian stimulation underwent PB biopsy. Patients with repeated implantation failure who were candidates for blastocyst transfer received trophectoderm biopsy. Zygotes or blastocysts were vitrified while chromosome analysis took place. Euploid embryos were transferred during a subsequent cycle. MAIN OUTCOME MEASURE(S): Cytogenetic status and implantation and pregnancy rates. RESULT(S): The oocyte and blastocyst aneuploidy rates were 65.5% and 45.2%, respectively. Abnormalities affecting all chromosomes were detected. Implantation and pregnancy rates for the patients with PB biopsy were 11.5% and 21.4%, respectively, whereas for patients receiving blastocyst analysis they were 58.3% and 69.2%. CONCLUSION(S): Initial results for patients of advanced maternal age (39.8 years) with repeated implantation failure and poor ovarian response were encouraging. However, further study is required to confirm whether or not screening is beneficial. Blastocyst analysis was associated with high pregnancy rates, suggesting that comprehensive chromosome screening may assist patients with repeated implantation failure capable of producing blastocysts in achieving pregnancies.

Preimplantation genetic diagnosis of single-gene disorders: experience with more than 200 cycles conducted by a reference laboratory in the United States.

OBJECTIVE: To evaluate trends and outcomes from preimplantation genetic diagnosis (PGD) cycles. DESIGN: Retrospective data review. SETTING: A reference laboratory specializing in the provision of PGD services. PATIENT(S): One hundred sixty-two patients at risk of transmitting a serious monogenic disorder to their children. INTERVENTION(S): In vitro fertilization and PGD. MAIN OUTCOME MEASURE(S): Results of PGD cycles. RESULT(S): Two hundred twenty-four PGD cycles were referred by 59 different IVF centers. Forty-six different disorders were diagnosed, including several not previously diagnosed at the preimplantation stage. Cystic fibrosis was the most common reason for referral (73 cases). A diagnosis was obtained for 84.4% of tested embryos, with results available 6 to 36 hours from sample receipt. Only 10.7% of cycles had no transfer. The pregnancy rate per cycle with ET was 43.4%. CONCLUSION(S): Unlike previous reports of multiple PGD cycles, all of the cases in this study involved shipping of biopsied cells to a specialist reference laboratory for diagnosis. This approach, sometimes referred to as "transport PGD," accounts for the vast majority of PGD cycles in the United States. Preimplantation genetic diagnosis was shown to be an effective alternative to prenatal diagnosis for patients with an ethical or a religious objection to pregnancy termination and for infertile patients carrying a genetic disorder. Demand for this service at our center doubled in each of the last 4 years. Pregnancy rates per ET were encouraging, almost half of all patients undergoing their first PGD cycle achieving a birth or ongoing pregnancy.