Non-invasive preimplantation genetic screening of human blastocysts

stage and then cryopreserved. When a non-diagnostic result was obtained, embryos were warmed for repeat biopsy and recryopreserved or, in rare cases, transferred on the same day of rapid PGS reanalysis. The control group consisted of embryos that did not initially undergo PGS prior to cryopreservation, but were later warmed, biopsied, found to be euploid, and subsequently transferred. PGS was performed using real-time PCR or next generation sequencing (NGS), depending upon the platform being utilized in the genetics laboratory at the time of analysis. Sustained implantation rates (SIRs) and clinical loss rates were compared using Pearson’s chi square test. RESULTS: Frozen embryo transfers involving 104 rebiopsied euploid embryos were available for review. The control group contained 570 previously cryopreserved euploid embryos transferred after a single biopsy. There were no differences in sustained implantation rates or clinical loss rates between the two groups. CONCLUSIONS: Pregnancy rates after transfer of euploid embryos that require repeat biopsy are comparable to those following transfer of euploid embryos that are subjected to warming and biopsy for initial PGS analysis. This finding suggests that repeat biopsy itself does not harm the reproductive potential of the embryo. Patients should be counseled that embryos can be safely rebiopsied in order to obtain a diagnostic result and, if euploid upon reanalysis, can be subsequently transferred with acceptable pregnancy rates. Outcomes following transfer of euploid embryos after rebiopsy compared to those only biopsied once

SIR Clinical loss rate

Study group (n¼104)

Control group (n¼570)

P-value

48.1% 18.3%

49.4% 15.3%

0.81 0.44

P-444 Wednesday, November 1, 2017 NON-INVASIVE PREIMPLANTATION GENETIC SCREENING OF HUMAN BLASTOCYSTS. V. Kuznyetsov,a S. Madjunkova,b R. Antes,c R. Abramov,d G. Motamedi,e Z. Ibarrientos,f C. L. Librach.d aPreimplantation Genetics Program, CReATe Fertility Centre, Toronto, ON, Canada; bPreimplantation Genetics, Create Fertility Centre, Toronto, ON, Canada; cCReATe Fertility Center, Toronto, ON, Canada; dCReATe Fertility Centre, Toronto, ON, Canada; eIVF Lab, Embryologist, Toronto, ON, Canada; fCreate Fertility Centre, Toronto, ON, Canada. OBJECTIVE: Trophectoderm biopsy (TB) and preimplantation genetic screening (PGS) for 24-chromosome aneuploidy using array comparative genomic hybridization (aCGH) and next-generation sequencing (NGS), significantly improves clinical reproductive outcomes. Although TB is a safe procedure if performed by experienced embryologists, development of non-invasive comprehensive chromosome screening, without embryo biopsy, eliminates any risk of embryo damage. The objective of this study was to determine if spent blastocyst culture medium (SBM) and blastocoele fluid (BF), derived from vitrified-warmed blastocysts, could be used for noninvasive preimplantation genetic screening (NIPGS). DESIGN: NIPGS samples (SBM+BF) were analyzed for chromosomal abnormalities and results were compared with the corresponding TB and/ or whole blastocyst (WB) samples. MATERIALS AND METHODS: Warmed Day 5/6 blastocysts, donated for research, were cultured in separate 25ml droplets (Global HP medium with HSA (LifeGlobal). After24 hours, the blastocysts were collapsed by a laser pulse, and then both SBM and BF samples were collected together as one NIPGS sample into PCR tubes. As a negative control we used the same media without embryo culture. SurePlex kit (BlueGnome) was used for whole genome amplification (WGA) of TB, NIPGS and WB samples. NGS by VeriSeq PGS (Illumina) was used to determine concordance rates for whole chromosome copy number between NIPGS and TB and WB samples. RESULTS: After WGA, the amplification rate of NIPGS samples was 100% (25/25). The concordance rate for whole chromosome copy number between a)NIPGS vs. TB, b)NIPGS vs. WB and c)TB vs. WB samples was 85.0% (17/20); 94.4% (17/18) and 85.7% (12/14) respectively. All NIPGS samples successfully identified the gender of the embryos. Our results showed that whole chromosome (12 samples) and segmental (2 samples) aneuploidies as well as chromosomal mosaicism (2 samples) could be detected in the NIPGS samples using NGS. CONCLUSIONS: Genomic DNA from NIPGS samples derived from vitrified-warmed blastocysts can be amplified and used for aneuploidy

FERTILITY & STERILITYÒ

screening, exhibiting almost full concordance with invasive testing. Additional studies are needed to improve this technology for potential translation into standard clinical genetic testing. Supported by: CREATE FERTILITY CENTRE P-445 Wednesday, November 1, 2017 NONINVASIVE CHROMOSOME SCREENING IMPROVES THE CLINICAL OUTCOMES IN FROZENTHAWED SINGLE BLASTOCYST TRANSFER CYCLES. C. Liyi,a S. Lu,b R. Fang,a X. Zhao.a aCentre for Reproductive Medicine, Wuxi Maternity and Child Health Hospital, Wuxi, China; bClinical Research, Yikon Genomics, Shanghai, China. OBJECTIVE: To perform a clinical evaluation of the efficacy of single embryo transfer at blastocyst stage selected using the noninvasive chromosome screening (NICS) assay, which involves the sequencing of free genomic DNA in the culture medium of individual blastocysts for obtaining chromosomal ploidy information. DESIGN: A retrospective observational study from September 2015 to September 2016. MATERIALS AND METHODS: A total of 353 frozen-thawed single blastocyst transfer (SBT) cycles were divided into three groups with different blastocyst selection criteria: the first was the No-choice group which had only one blastocyst for transfer for each patient (n¼285). The second was the Morphology group. The patients of this group had at least two blastocysts available and blastocysts were selected for single blastocyst transfer on the basis of traditional morphological assessments (n¼41); the third was the NICS group that had at least two blastocysts for each patient and the euploid blastocysts were selected using NICS for single blastocyst transfer (n¼27). RESULTS: The biochemical pregnancy rate in the No-choice group, the Morphology group and the NICS group was 65.3%, 65.9% and 85.2%, respectively (P¼0.232). Among three groups, the NICS group had the highest implantation rate (63.0%) (P¼0.193), compared with 56.1% and 45.3% in the Morphology group and the No-choice group, respectively. There was no incidence of early miscarriage in the NICS group, while the early miscarriage rate in the No-choice group and the Morphology group was 21.1% and 13.0%, respectively (P¼0.094). A significant difference was found in the ongoing pregnancy rate among the three groups, which was highest in the NICS group (63.0%) and lowest in the No-choice group (37.9%) (P¼0.016). CONCLUSIONS: NICS is a novel genetic testing that allows an accurate selection of blastocysts with better developmental potential for transfer and might improve the clinical outcomes. P-446 Wednesday, November 1, 2017 HIGH EFFICACY OF NON-INVASIVE CHROMOSOME SCREENING USING SPENT CULTURE MEDIUM FOR PREIMPLANTATION GENETIC TESTING OF HUMAN EMBRYOS. L. Huang,a,b B. Bogale,a S. Lu,c X. S. Xie,b,d,e C. Racowsky.a,f aDept. of Ob/Gyn, Brigham & Women’s Hospital, Boston, MA; bDept. of Chemistry & Chemical Biology, Harvard University, Cambridge, MA; cDept. of Clinical Research, Yikon Genomics Company, Ltd., Shanghai, China; dBeijing Advanced Innovation Center for Genomics, Peking University, Beijing, China; eBiodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing, China; fHarvard Medical School, Boston, MA. OBJECTIVE: Preimplantation genetic screening (PGS) with trophectoderm (TE) biopsy, PGS-TE, is widely used in clinical IVF but embryo mosaicism and lack of suitability for biopsy of some embryos limits the technique. While ploidy of the biopsied TE cells is provided by PGS-TE, this may not reflect ploidy of the entire TE and/or that of the inner cell mass (ICM). An efficacious non-invasive chromosome screen (NICS) that provides ploidy for both the whole TE and the ICM, would therefore fill a much needed gap in clinical IVF. The present study targeted this gap by critically examining the utility of analyzing cell-free DNA in spent culture media for prediction of whole embryo ploidy. DESIGN: Cohort study of Day 5 human blastocysts comparing PGS-TE, NICS and whole embryo ploidy results. MATERIALS AND METHODS: Vitrified day 5 blastocysts from ICSI, previously tested with PGS-TE and donated under patient informed consent (n¼33), were warmed, cultured in 15 ul drops of Global Total under oil and, after 24hr, 10 ul spent media samples and corresponding embryos were collected. All samples were amplified by MALBAC subsequent to next

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