Selection of competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing for patients undergoing preimplantation genetic screening: a prospective study with sibling oocytes

Zhihong Yang, John Zhang, Shala A Salem, Xiaohong Liu, Yanping Kuang, Rifaat D Salem, Jiaen Liu, Zhihong Yang, John Zhang, Shala A Salem, Xiaohong Liu, Yanping Kuang, Rifaat D Salem, Jiaen Liu

Abstract

Background: Recent advances in time-lapse monitoring in IVF treatment have provided new morphokinetic markers for embryonic competence. However, there is still very limited information about the relationship between morphokinetic parameters, chromosomal compositions and implantation potential. Accordingly, this study aimed at investigating the effects of selecting competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing on pregnancy and implantation outcomes for patients undergoing preimplantation genetic screening (PGS).

Methods: A total of 1163 metaphase II (MII) oocytes were retrieved from 138 PGS patients at a mean age of 36.6 ± 2.4 years. These sibling MII oocytes were then randomized into two groups after ICSI: 1) Group A, oocytes (n = 582) were cultured in the time-lapse system and 2) Group B, oocytes (n = 581) were cultured in the conventional incubator. For both groups, whole genomic amplification and array CGH testing were performed after trophectoderm biopsy on day 5. One to two euploid blastocysts within the most predictive morphokinetic parameters (Group A) or with the best morphological grade available (Group B) were selected for transfer to individual patients on day 6. Ongoing pregnancy and implantation rates were compared between the two groups.

Results: There were significant differences in clinical pregnancy rates between Group A and Group B (71.1% vs. 45.9%, respectively, p = 0.037). The observed implantation rate per embryo transfer significantly increased in Group A compared to Group B (66.2% vs. 42.4%, respectively, p = 0.011). Moreover, a significant increase in ongoing pregnancy rates was also observed in Group A compared to Group B (68.9% vs. 40.5%. respectively, p = 0.019). However, there was no significant difference in miscarriage rate between the time-lapse system and the conventional incubator (3.1% vs. 11.8%, respectively, p = 0.273).

Conclusions: This is the first prospective investigation using sibling oocytes to evaluate the efficiency of selecting competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing for PGS patients. Our data clearly demonstrate that the combination of these two advanced technologies to select competent blastocysts for transfer results in improved implantation and ongoing pregnancy rates for PGS patients.

Figures

Figure 1
Figure 1
Schematic for oocytes randomized into either the time-lapse system (Group A) or the conventional incubator (Group B). GV = germinal vesicle; MI = metaphase I; MII = metaphase II; 2PN = two pronuclei; Excluded immature (GV and MI) oocytes and unfertilized oocytes in each group were circled in red. The total number of blastocysts associated with each group is circled in blue.
Figure 2
Figure 2
Representative array CGH profiles showing euploidy and different types of aneuploidy detected in both Group A and Group B. I. Euploid profile with normal chromosomal copies; II. Aneuploid profile with single chromosomal gain (trisomy): a gain of chromosome 16; III. Aneuploid profile with single chromosomal loss (monosomy): a loss of chromosome 6; IV. Aneuploid profile with dual chromosomal abnormalities: losses of chromosomes 6 and 10; V. Aneuploid profile with complex chromosomal abnormalities: a gain of chromosome 19 and losses of chromosomes 4 and 15.
Figure 3
Figure 3
Comparison of morphokinetic parameters of the early stages of embryonic development between euploid and aneuploid embryos in the time-lapse monitoring group. t2 = time from insemination to 2 cells; t3 = time from insemination to 3 cells; t5 = time from insemination to 5 cells; cc2 = time between division to 2 cells and division to 3 cells; s2 = time between division to 3 cells and subsequent division to 4 cells; hpi = hours post insemination. Morphokinetic data were presented as mean ± SD. There were no significant differences between euploid and aneuploid embryos in each of the morphokinetic parameters (p >0.05 by Mann–Whitney test).
Figure 4
Figure 4
Comparison of morphokinetic parameters of the later stages of embryonic development between euploid and aneuploid embryos in the time-lapse monitoring group. t8 = time from insemination to 8 cells; tM = time from insemination to formation of a compact morula; tIB = time from insemination to initiation of blastulation; tFB = time from insemination to formation of a full blastocyst. tEB = time from insemination to formation of a expanded blastocyst. Morphokinetic data were presented as mean ± SD. There were no significant differences between euploid and aneuploid embryos in each of the morphokinetic parameters (p >0.05 by Mann–Whitney test).

References

    1. Edwards RG, Purdy JM, Steptoe PC, Walters DE. The growth of human preimplantation embryos in vitro. Am J Obstet Gynecol. 1981;7:408–416.
    1. Racowsky C, Vernon M, Mayer J, Ball GD, Behr B, Pomeroy KO, Wininger D, Gibbons W, Conaghan J, Stern JE. Standardization of grading embryo morphology. J Assist Reprod Genet. 2010;7:437–439.
    1. Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology. The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting. Hum Reprod. 2011;7:1270–1283.
    1. Cummins JM, Breen TM, Harrison KL, Shaw JM, Wilson LM, Hennessey JF. A formula for scoring human embryo growth rates in in vitro fertilization: its value in predicting pregnancy and in comparison with visual estimates of embryo quality. J In Vitro Fert Embryo Transf. 1986;7:284–295.
    1. Giorgetti C, Terriou P, Auquier P, Hans E, Spach JL, Salzmann J, Roulier R. Embryo score to predict implantation after in-vitro fertilization: based on 957 single embryo transfers. Hum Reprod. 1995;7:2427–2431.
    1. Racowsky C, Ohno-Machado L, Kim J, Biggers JD. Is there an advantage in scoring early embryos on more than one day? Hum Reprod. 2009;7:2104–2113.
    1. Racowsky C, Combelles CMH, Nureddin A, Pan Y, Finn A, Miles L, Gale S, O'Leary T, Jackson KV. Day 3 and day 5 morphological predictors of embryo viability. Reprod Biomed Online. 2003;7:323–331.
    1. Scott L, Alvero R, Leondires M, Miller B. The morphology of human pronuclear embryos is positively related to blastocyst development and implantation. Hum Reprod. 2000;7:2394–2403.
    1. Chen C, Kattera S. Comparison of pronuclear zygote morphology and early cleavage status of zygotes as additional criteria in the selection of day 3 embryos: a randomized study. Fertil Steril. 2006;7:347–352.
    1. Gardner DK, Schoolcraft WB. Culture and transfer of human blastocysts. Curr Opin Obstet Gynecol. 1999;7:307–311.
    1. Alfarawati S, Fragouli E, Colls P, Stevens J, Gutierrez-Mateo C, Schoolcraft WB, Katz-Jaffe MG, Wells D. The relationship between blastocyst morphology, chromosomal abnormality, and embryo gender. Fertil Steril. 2011;7:520–524.
    1. Yang Z, Liu J, Collins GS, Salem SA, Liu X, Lyle SS, Peck AC, Sills ES, Salem RD. Selection of single blastocysts for fresh transfer via standard morphology assessment alone and with array CGH for good prognosis IVF patients: results from a randomized pilot study. Mol Cytogenet. 2012;7:24.
    1. Liu J, Sills ES, Yang Z, Salem SA, Rahil T, Collins GS, Liu X, Salem RD. Array comparative genomic hybridization screening in IVF significantly reduces number of embryos available for cryopreservation. Clin Exp Reprod Med. 2012;7:52–57.
    1. Yang Z, Salem SA, Liu X, Kuang Y, Salem RD, Liu J. Selection of euploid blastocysts for cryopreservation with array comparative genomic hybridization (aCGH) results in increased implantation rates in subsequent frozen and thawed embryo transfer cycles. Mol Cytogenet. 2013;7:32.
    1. Zhang JQ, Li XL, Peng Y, Guo X, Heng BC, Tong GQ. Reduction in exposure of human embryos outside the incubator enhances embryo quality and blastulation rate. Reprod Biomed Online. 2010;7:510–515.
    1. Calzi F, Papaleo E, Rabellotti E, Ottolina J, Vailati S, Vigano P, Candiani M. Exposure of embryos to oxygen at low concentration in a cleavage stage transfer program: reproductive outcomes in a time-series analysis. Clin Lab. 2012;7:997–1003.
    1. Swain JE. Optimizing the culture environment in the IVF laboratory: impact of pH and buffer capacity on gamete and embryo quality. Reprod Biomed Online. 2010;7:6–16.
    1. Gomes Sobrinho DB, Oliveira JBA, Petersen CG, Mauri AL, Silva LFI, Massaro FC, Baruffi RLR, Cavagna M, Franco JG. IVF/ICSI outcomes after culture of human embryos at low oxygen tension: a meta-analysis. Reprod Biol Endocrinol. 2011;7:143.
    1. Pickering SJ, Braude PR, Johnson MH, Cant A, Currie J. Transient cooling to room temperature can cause irreversible disruption of the meiotic spindle in the human oocyte. Fertil Steril. 1990;7:102–108.
    1. Campbell A, Fishel S, Bowman N, Duffy S, Sedler M, Hickman CFL. Modelling a risk classification of aneuploidy in human embryos using non-invasive morphokinetics. Reprod Biomed Online. 2013;7:477–485.
    1. Campbell A, Fishel S, Bowman N, Duffy S, Sedler M, Thornton S. Retrospective analysis of outcomes after IVF using an aneuploidy risk model derived from time-lapse imaging without PGS. Reprod Biomed Online. 2013;7:140–146.
    1. Payne D, Flaherty SP, Barry MF, Matthews CD. Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography. Hum Reprod. 1997;7:532–541.
    1. Mio Y, Maeda K. Time-lapse cinematography of dynamic changes occurring during in vitro development of human embryos. Am J Obstet Gynecol. 2008;7:1–5.
    1. Lemmen JG, Agerholm I, Ziebe S. Kinetic markers of human embryo quality using time-lapse recordings of IVF/ICSI-fertilized oocytes. Reprod Biomed Online. 2008;7:385–391.
    1. Arav A, Aroyo A, Yavin S, Roth Z. Prediction of embryonic developmental competence by time-lapse observation and 'shortest-half' analysis. Reprod Biomed Online. 2008;7:669–675.
    1. Meseguer M, Herrero J, Tejera A, Hilligsoe KM, Ramsing NB, Remohi J. The use of morphokinetics as a predictor of embryo implantation. Hum Reprod. 2011;7:2658–2671.
    1. Rubio I, Kuhlmann R, Agerholm I, Kirk J, Herrero J, Escriba M-J, Bellver J, Meseguer M. Limited implantation success of direct-cleaved human zygotes: a time-lapse study. Fertil Steril. 2012;7:1458–1463.
    1. Wong CC, Loewke KE, Bossert NL, Behr B, De Jonge CJ, Baer TM, Reijo Pera RA. Non-invasive imaging of human embryos before embryonic genome activation predicts development to the blastocyst stage. Nat Biotechnol. 2010;7:1115–1121.
    1. Pribenszky C, Matyas S, Kovacs P, Losonczi E, Zadori J, Vajta G. Pregnancy achieved by transfer of a single blastocyst selected by time-lapse monitoring. Reprod Biomed Online. 2010;7:533–536.
    1. Ciray HN, Aksoy T, Goktas C, Ozturk B, Bahceci M. Time-lapse evaluation of human embryo development in single versus sequential culture media–a sibling oocyte study. J Assist Reprod Genet. 2012;7:891–900.
    1. Kirkegaard K, Hindkjaer JJ, Ingerslev HJ. Human embryonic development after blastomere removal: a time-lapse analysis. Hum Reprod. 2012;7:97–105.
    1. Cruz M, Gadea B, Garrido N, Pedersen KS, Martinez M, Perez-Cano I, Munoz M, Meseguer M. Embryo quality, blastocyst and ongoing pregnancy rates in oocyte donation patients whose embryos were monitored by time-lapse imaging. J Assist Reprod Genet. 2011;7:569–573.
    1. Kirkegaard K, Hindkjaer JJ, Grondahl ML, Kesmodel US, Ingerslev HJ. A randomized clinical trial comparing embryo culture in a conventional incubator with a time-lapse incubator. J Assist Reprod Genet. 2012;7:565–572.
    1. Meseguer M, Rubio I, Cruz M, Basile N, Marcos J, Requena A. Embryo incubation and selection in a time-lapse monitoring system improves pregnancy outcome compared with a standard incubator: a retrospective cohort study. Fertil Steril. 2012;7:1481–1489.
    1. Conaghan J, Chen AA, Willman SP, Ivani K, Chenette PE, Boostanfar R, Baker VL, Adamson G, Abusief M, Gvakharia M, Loewke KE, Shen S. Improving embryo selection using a computer-automated time-lapse image analysis test plus day 3 morphology: results from a prospective multicenter trial. Fertil Steril. 2013;7:412–419.
    1. Kirkegaard K, Kesmodel US, Hindkjær JJ, Ingerslev HJ. Time-lapse as predictors of blastocyst development and pregnancy outcome in embryos from good prognosis patients: a prospective cohory study. Hum Reprod. 2013;7:2643–2651.
    1. Hodes-Wertz B, Grifo J, Ghadir S, Kaplan B, Laskin CA, Glassner M, Munne S. Idiopathic recurrent miscarriage is caused mostly by aneuploid embryos. Fertil Steril. 2012;7:675–680.
    1. Wilton L. Preimplantation genetic diagnosis and chromosome analysis of blastomeres using comparative genomic hybridization. Hum Reprod Update. 2005;7:33–41.
    1. Munne S, Alikani M, Tomkin G, Grifo J, Cohen J. Embryo morphology, developmental rates, and maternal age are correlated with chromosome abnormalities. Fertil Steril. 1995;7:382–391.
    1. Hassold T, Hunt P. Maternal age and chromosomally abnormal pregnancies: what we know and what we wish we knew. Curr Opin Pediatr. 2009;7:703–708.
    1. Kuliev A, Cieslak J, Verlinsky Y. Frequency and distribution of chromosome abnormalities in human oocytes. Cytogenet Genome Res. 2005;7:193–198.
    1. Mantzouratou A, Delhanty JDA. Aneuploidy in the human cleavage stage embryo. Cytogenet Genome Res. 2011;7:141–148.
    1. Fragouli E, Wells D. Aneuploidy in the human blastocyst. Cytogenet Genome Res. 2011;7:149–159.
    1. Rubio C, Simon C, Vidal F, Rodrigo L, Pehlivan T, Remohi J, Pellicer A. Chromosomal abnormalities and embryo development in recurrent miscarriage couples. Hum Reprod. 2003;7:182–188.
    1. Voullaire L, Wilton L, McBain J, Callaghan T, Williamson R. Chromosome abnormalities identified by comparative genomic hybridization in embryos from women with repeated implantation failure. Mol Hum Reprod. 2002;7:1035–1041.
    1. Munne S, Sandalinas M, Magli C, Gianaroli L, Cohen J, Warburton D. Increased rate of aneuploid embryos in young women with previous aneuploid conceptions. Prenat Diagn. 2004;7:638–643.
    1. Handyside AH, Kontogianni EH, Hardy K, Winston RM. Pregnancies from biopsied human preimplantation embryos sexed by Y-specific DNA amplification. Nature. 1990;7:768–770.
    1. Handyside AH, Lesko JG, Tarin JJ, Winston RM, Hughes MR. Birth of a normal girl after in vitro fertilization and preimplantation diagnostic testing for cystic fibrosis. N Engl J Med. 1992;7:905–909.
    1. Liu J, Lissens W, Devroey P, Liebaers I, Van Steirteghem AC. Efficiency of polymerase chain reaction assay for cystic fibrosis in single human blastomeres according to the presence or absence of nuclei. Fertil Steril. 1993;7:815–819.
    1. Delhanty JD, Griffin DK, Handyside AH, Harper J, Atkinson GH, Pieters MH, Winston RM. Detection of aneuploidy and chromosomal mosaicism in human embryos during preimplantation sex determination by fluorescent in situ hybridisation, (FISH) Hum Mol Genet. 1993;7:1183–1185.
    1. Munne S, Lee A, Rosenwaks Z, Grifo J, Cohen J. Diagnosis of major chromosome aneuploidies in human preimplantation embryos. Hum Reprod. 1993;7:2185–2191.
    1. Harper JC, Delhanty JD. Detection of chromosomal abnormalities in human preimplantation embryos using FISH. J Assist Reprod Genet. 1996;7:137–139.
    1. Gianaroli L, Magli MC, Ferraretti AP, Fiorentino A, Garrisi J, Munne S. Preimplantation genetic diagnosis increases the implantation rate in human in vitro fertilization by avoiding the transfer of chromosomally abnormal embryos. Fertil Steril. 1997;7:1128–1131.
    1. Staessen C, Verpoest W, Donoso P, Haentjens P, Van der Elst J, Liebaers I, Devroey P. Preimplantation genetic screening does not improve delivery rate in women under the age of 36 following single-embryo transfer. Hum Reprod. 2008;7:2818–2825.
    1. Hardarson T, Hanson C, Lundin K, Hillensjo T, Nilsson L, Stevic J, Reismer E, Borg K, Wikland M, Bergh C. Preimplantation genetic screening in women of advanced maternal age caused a decrease in clinical pregnancy rate: a randomized controlled trial. Hum Reprod. 2008;7:2806–2812.
    1. Schoolcraft WB, Katz-Jaffe MG, Stevens J, Rawlins M, Munne S. Preimplantation aneuploidy testing for infertile patients of advanced maternal age: a randomized prospective trial. Fertil Steril. 2009;7:157–162.
    1. Debrock S, Melotte C, Spiessens C, Peeraer K, Vanneste E, Meeuwis L, Meuleman C, Frijns J-P, Vermeesch JR, D'Hooghe TM. Preimplantation genetic screening for aneuploidy of embryos after in vitro fertilization in women aged at least 35 years: a prospective randomized trial. Fertil Steril. 2010;7:364–373.
    1. Wells D, Delhanty JD. Comprehensive chromosomal analysis of human preimplantation embryos using whole genome amplification and single cell comparative genomic hybridization. Mol Hum Reprod. 2000;7:1055–1062.
    1. Voullaire L, Wilton L, Slater H, Williamson R. Detection of aneuploidy in single cells using comparative genomic hybridization. Prenat Diagn. 1999;7:846–851.
    1. Fragouli E, Lenzi M, Ross R, Katz-Jaffe M, Schoolcraft WB, Wells D. Comprehensive molecular cytogenetic analysis of the human blastocyst stage. Hum Reprod. 2008;7:2596–2608.
    1. Sher G, Keskintepe L, Keskintepe M, Maassarani G, Tortoriello D, Brody S. Genetic analysis of human embryos by metaphase comparative genomic hybridization (mCGH) improves efficiency of IVF by increasing embryo implantation rate and reducing multiple pregnancies and spontaneous miscarriages. Fertil Steril. 2009;7:1886–1894.
    1. Schoolcraft WB, Fragouli E, Stevens J, Munne S, Katz-Jaffe MG, Wells D. Clinical application of comprehensive chromosomal screening at the blastocyst stage. Fertil Steril. 2010;7:1700–1706.
    1. Gutierrez-Mateo C, Colls P, Sanchez-Garcia J, Escudero T, Prates R, Ketterson K, Wells D, Munne S. Validation of microarray comparative genomic hybridization for comprehensive chromosome analysis of embryos. Fertil Steril. 2011;7:953–958.
    1. Fishel S, Gordon A, Lynch C, Dowell K, Ndukwe G, Kelada E, Thornton S, Jenner L, Cater E, Brown A, Garcia-Benardo J. Live birth after polar body array comparative genomic hybridization prediction of embryo ploidy-the future of IVF? Fertil Steril. 2010;7:1006. e7-e10.
    1. Alfarawati S, Fragouli E, Colls P, Wells D. First births after preimplantation genetic diagnosis of structural chromosome abnormalities using comparative genomic hybridization and microarray analysis. Hum Reprod. 2011;7:1560–1574.
    1. Fiorentino F, Spizzichino L, Bono S, Biricik A, Kokkali G, Rienzi L, Ubaldi FM, Iammarrone E, Gordon A, Pantos K. PGD for reciprocal and Robertsonian translocations using array comparative genomic hybridization. Hum Reprod. 2011;7:1925–1935.
    1. Gabriel AS, Thornhill AR, Ottolini CS, Gordon A, Brown APC, Taylor J, Bennett K, Handyside A, Griffin DK. Array comparative genomic hybridisation on first polar bodies suggests that non-disjunction is not the predominant mechanism leading to aneuploidy in humans. J Med Genet. 2011;7:433–437.
    1. Geraedts J, Montag M, Magli MC, Repping S, Handyside A, Staessen C, Harper J, Schmutzler A, Collins J, Goossens V, van der Ven H, Vesela K, Gianaroli L. Polar body array CGH for prediction of the status of the corresponding oocyte. Part I: clinical results. Hum Reprod. 2011;7:3173–3180.
    1. Fragouli E, Alfarawati S, Daphnis DD, Goodall NN, Mania A, Griffiths T, Gordon A, Wells D. Cytogenetic analysis of human blastocysts with the use of FISH, CGH and aCGH: scientific data and technical evaluation. Hum Reprod. 2011;7:480–490.
    1. Liu J, Wang W, Sun X, Liu L, Jin H, Li M, Witz C, Williams D, Griffith J, Skorupski J, Haddad G, Gill J. DNA microarray reveals that high proportions of human blastocysts from women of advanced maternal age are aneuploid and mosaic. Biol Reprod. 2012;7:148–148.
    1. Capalbo A, Bono S, Spizzichino L, Biricik A, Baldi M, Colamaria S, Ubaldi FM, Rienzi L, Fiorentino F. Sequential comprehensive chromosome analysis on polar bodies, blastomeres and trophoblast: insights into female meiotic errors and chromosomal segregation in the preimplantation window of embryo development. Hum Reprod. 2013;7:509–518.
    1. Handyside AH. PGD and aneuploidy screening for 24 chromosomes by genome-wide SNP analysis: seeing the wood and the trees. Reprod Biomed Online. 2011;7:686–691.
    1. Treff NR, Su J, Tao X, Levy B, Scott RT. Accurate single cell 24 chromosome aneuploidy screening using whole genome amplification and single nucleotide polymorphism microarrays. Fertil Steril. 2010;7:2017–2021.
    1. Northrop LE, Treff NR, Levy B, Scott RT Jr. SNP microarray-based 24 chromosome aneuploidy screening demonstrates that cleavage-stage FISH poorly predicts aneuploidy in embryos that develop to morphologically normal blastocysts. Mol Hum Reprod. 2010;7:590–600.
    1. Johnson DS, Gemelos G, Baner J, Ryan A, Cinnioglu C, Banjevic M, Ross R, Alper M, Barrett B, Frederick J, Potter D, Behr B, Rabinowitz M. Preclinical validation of a microarray method for full molecular karyotyping of blastomeres in a 24-h protocol. Hum Reprod. 2010;7:1066–1075.
    1. Lathi RB, Massie JAM, Gilani M, Milki AA, Westphal LM, Baker VL, Behr B. Outcomes of trophectoderm biopsy on cryopreserved blastocysts: a case series. Reprod Biomed Online. 2012;7:504–507.
    1. Scott RT, Jr, Upham KM, Forman EJ, Hong KH, Scott KL, Talor D, Tao X, Treff NR. Blastocyst biopsy with comprehensive chromosome screening and fresh embryo transfer significantly increases in vitro fertilization implantation and delivery rates: a randomized controlled trial. Fertil Steril. in press.
    1. Scott RT, Ferry K, Su J, Tao X, Scott K, Treff NR. Comprehensive chromosome screening is highly predictive of the reproductive potential of human embryos: a prospective, blinded, nonselection study. Fertil Steril. 2012;7:870–875.
    1. Treff NR, Tao X, Ferry KM, Su J, Taylor D, Scott RT. Development and validation of an accurate quantitative real-time polymerase chain reaction-based assay for human blastocyst comprehensive chromosomal aneuploidy screening. Fertil Steril. 2012;7:819–824.
    1. Forman EJ, Tao X, Ferry KM, Taylor D, Treff NR, Scott RT. Single embryo transfer with comprehensive chromosome screening results in improved ongoing pregnancy rates and decreased miscarriage rates. Hum Reprod. 2012;7:1217–1222.
    1. Catt JW, Henman M. Toxic effects of oxygen on human embryo development. Hum Reprod. 2000;7(Suppl 2):199–206.
    1. Meintjes M, Chantilis SJ, Douglas JD, Rodriguez AJ, Guerami AR, Bookout DM, Barnett BD, Madden JD. A controlled randomized trial evaluating the effect of lowered incubator oxygen tension on live births in a predominantly blastocyst transfer program. Hum Reprod. 2009;7:300–307.
    1. Yang HW, Hwang KJ, Kwon HC, Kim HS, Choi KW, Oh KS. Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos. Hum Reprod. 1998;7:998–1002.
    1. Kovacic B, Vlaisavljevic V. Influence of atmospheric versus reduced oxygen concentration on development of human blastocysts in vitro: a prospective study on sibling oocytes. Reprod Biomed Online. 2008;7:229–236.
    1. Capalbo A, Wright G, Elliot T, Ubaldi FM, Rienzi L, Nagy ZP. FISH reananlysis of inner cell mass and trophectoderm samples of previously array-CGH screened blastocysts shows high accuracy of diagnosis and no major diagnostic impact of mosaicism at the blastocyst stage. Hum Reprod. 2013;7:2298–2307.
    1. Niemitz EL, Feinberg AP. Epigenetics and assisted reproductive technology: a call for investigation. Am J Hum Genet. 2004;7:599–609.
    1. Horsthemke B, Ludwig M. Assisted reproduction: the epigenetic perspective. Hum Reprod Update. 2005;7:473–482.

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