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Intracytoplasmic sperm injection

Kathleen Miller, DHSC
Section Editor
Robert L Barbieri, MD
Deputy Editor
Kristen Eckler, MD, FACOG


Intracytoplasmic sperm injection (ICSI) refers to a technique in which a single sperm is injected directly into the cytoplasm of a mature oocyte. This procedure is performed as part of an in vitro fertilization (IVF) cycle, and provides an effective method for assisting fertilization in men with suboptimal semen parameters or who experienced no or low fertilization rates after conventional IVF.

ICSI was first applied to human gametes in 1988 [1]; it was first used in cases of fertilization failure after standard IVF or when few sperm cells were available. The first pregnancies were reported in Belgium in 1992 [2]. This technique has consistently demonstrated higher fertilization rates than prior micromanipulation techniques, and produced more embryos with higher implantation rates [2-5]. The capacity of ICSI to permit almost any type of spermatozoa to fertilize oocytes has made it the most successful treatment for male factor infertility. In 2008, IVF with ICSI comprised 64.3 percent of ART procedures in the United States, IVF without ICSI comprised 35.5 percent; GIFT, ZIFT, or a combination of procedures accounted for the remainder [6]. The use of ICSI in the United States has increased dramatically since 1995, without a proportionate increase in diagnosis of male-factor infertility [7]. The use of ICSI for male factor infertility increased from 84 percent in 2003 to 93 percent in 2012 [8,9]. Worldwide, there is geographic variation in the use of ICSI with IVF [10].

This topic discusses the indications, techniques, and outcomes for ICSI. Other treatments for male infertility are discussed elsewhere. (See "Treatment of male infertility".)


A thorough evaluation of the male patient, including semen analysis [11,12], sperm morphology [13], and urology consultation is warranted. Although controversial, some authorities also utilize additional tests such as sperm antibody testing [14], and a wide spectrum of spermatozoa function tests ranging from, but not limited to, hamster-spermatozoa penetration assay, hemi-zona assay, mannose binding assay, hypo-osmotic swelling test, and acrosome reaction assay [15-20] for identifying couples at risk for reduced or no fertilization with conventional IVF [13,21-25]. In males with severe oligospermia or azoospermia, additional testing may be recommended. (See "Evaluation of male infertility".)

The most common genetic factors associated with male infertility are cystic fibrosis gene mutations (associated with congenital absence of the vas deferens), structural chromosomal abnormalities (eg, aneuploidy, inversion, translocation) associated with impaired testicular function, and Y chromosome microdeletions (associated with impaired spermatogenesis). Cystic fibrosis is associated with a mutation of the cystic fibrosis transmembrane conductance regulator gene. Men who carry this gene may not have the classic clinical manifestations of cystic fibrosis. (See "Causes of male infertility", section on 'Disorders of sperm transport'.)


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Literature review current through: May 2017. | This topic last updated: May 09, 2017.
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  1. Lanzendorf SE, Maloney MK, Veeck LL, et al. A preclinical evaluation of pronuclear formation by microinjection of human spermatozoa into human oocytes. Fertil Steril 1988; 49:835.
  2. Palermo G, Joris H, Devroey P, Van Steirteghem AC. Pregnancies after intracytoplasmic injection of single spermatozoon into an oocyte. Lancet 1992; 340:17.
  3. Cohen J. A review of clinical microsurgical fertilization. In: Micromanipulation of Human Gametes and Embryos, Cohen J, Malter HE, Talansky BF (Eds), Raven Press, New York 1992. p.63.
  4. Wada I, Macnamee M, Brinsden P. Prevention and treatment of ovarian hyperstimulation. Hum Reprod 1993; 8:2245.
  5. Van Steirteghem AC, Liu J, Joris H, et al. Higher success rate by intracytoplasmic sperm injection than by subzonal insemination. Report of a second series of 300 consecutive treatment cycles. Hum Reprod 1993; 8:1055.
  6. http://www.cdc.gov/art/ART2008/PDF/ART_2008_Full.pdf (Accessed on September 23, 2011).
  7. Jain T, Gupta RS. Trends in the use of intracytoplasmic sperm injection in the United States. N Engl J Med 2007; 357:251.
  8. Shridharani A, Sandlow JI. Vasectomy reversal versus IVF with sperm retrieval: which is better? Curr Opin Urol 2010; 20:503.
  9. Boulet SL, Mehta A, Kissin DM, et al. Trends in use of and reproductive outcomes associated with intracytoplasmic sperm injection. JAMA 2015; 313:255.
  10. Nyboe Andersen A, Carlsen E, Loft A. Trends in the use of intracytoplasmatic sperm injection marked variability between countries. Hum Reprod Update 2008; 14:593.
  11. World Health Organization, WHO Laboratory Manual for Examination of Human Semen and Semen-Cervical Mucus Interaction, Cambridge University Press, Cambridge 1999.
  12. Menkveld R, Wong WY, Lombard CJ, et al. Semen parameters, including WHO and strict criteria morphology, in a fertile and subfertile population: an effort towards standardization of in-vivo thresholds. Hum Reprod 2001; 16:1165.
  13. Kruger TF, Acosta AA, Simmons KF, et al. Predictive value of abnormal sperm morphology in in vitro fertilization. Fertil Steril 1988; 49:112.
  14. Clarke, GN. Detection of antisperm antibodies using Immunobeads, In: Handbook of the Laboratory Diagnosis and Treatment of Infertility, Keel, BA, Webster, BW (Eds), CRC, Boca Raton, Florida 1990. p.177.
  15. Overstreet JW, Yanagimachi R, Katz DF, et al. Penetration of human spermatozoa into the human zona pellucida and the zona-free hamster egg: a study of fertile donors and infertile patients. Fertil Steril 1980; 33:534.
  16. Oehninger S, Coddington CC, Scott R, et al. Hemizona assay: assessment of sperm dysfunction and prediction of in vitro fertilization outcome. Fertil Steril 1989; 51:665.
  17. Benoff S, Cooper GW, Hurley I, et al. Human sperm fertilizing potential in vitro is correlated with differential expression of a head-specific mannose-ligand receptor. Fertil Steril 1993; 59:854.
  18. Barratt CL, Osborn JC, Harrison PE, et al. The hypo-osmotic swelling test and the sperm mucus penetration test in determining fertilization of the human oocyte. Hum Reprod 1989; 4:430.
  19. Liu DY, Baker HW. Acrosome status and morphology of human spermatozoa bound to the zona pellucida and oolemma determined using oocytes that failed to fertilize in vitro. Hum Reprod 1994; 9:673.
  20. Freeman MR, Archibong AE, Mrotek JJ, et al. Male partner screening before in vitro fertilization: preselecting patients who require intracytoplasmic sperm injection with the sperm penetration assay. Fertil Steril 2001; 76:1113.
  21. Jeulin C, Feneux D, Serres C, et al. Sperm factors related to failure of human in-vitro fertilization. J Reprod Fertil 1986; 76:735.
  22. Liu DY, Baker HW. Tests of human sperm function and fertilization in vitro. Fertil Steril 1992; 58:465.
  23. Mortimer D. The essential partnership between diagnostic andrology and modern assisted reproductive technologies. Hum Reprod 1994; 9:1209.
  24. Baker, G, Lui, DY, Bourne, H. Assessment of the male and preparation of sperm for ARTs. In: Handbook of in vitro Fertilization, 2nd ed, Trounson, AO, Gardner, DK (Eds), CRC Press 2000.
  25. Liu DY, Garrett C, Baker HW. Clinical application of sperm-oocyte interaction tests in in vitro fertilization--embryo transfer and intracytoplasmic sperm injection programs. Fertil Steril 2004; 82:1251.
  26. Male Infertility Best Practice Policy Committee of the American Urological Association, Practice Committee of the American Society for Reproductive Medicine. Report on optimal evaluation of the infertile male. Fertil Steril 2006; 86:S202.
  27. Kurinczuk JJ. Safety issues in assisted reproduction technology. From theory to reality--just what are the data telling us about ICSI offspring health and future fertility and should we be concerned? Hum Reprod 2003; 18:925.
  28. Practice Committees of the American Society for Reproductive Medicine and Society for Assisted Reproductive Technology. Intracytoplasmic sperm injection (ICSI) for non-male factor infertility: a committee opinion. Fertil Steril 2012; 98:1395.
  29. Practice Committee of American Society for Reproductive Medicine. Intracytoplasmic sperm injection (ICSI). Fertil Steril 2008; 90:S187.
  30. Palermo GD, Neri QV, Takeuchi T, Rosenwaks Z. ICSI: where we have been and where we are going. Semin Reprod Med 2009; 27:191.
  31. Johnson LN, Sasson IE, Sammel MD, Dokras A. Does intracytoplasmic sperm injection improve the fertilization rate and decrease the total fertilization failure rate in couples with well-defined unexplained infertility? A systematic review and meta-analysis. Fertil Steril 2013; 100:704.
  32. Tournaye H, Verheyen G, Albano C, et al. Intracytoplasmic sperm injection versus in vitro fertilization: a randomized controlled trial and a meta-analysis of the literature. Fertil Steril 2002; 78:1030.
  33. Silber SJ, Van Steirteghem AC, Liu J, et al. High fertilization and pregnancy rate after intracytoplasmic sperm injection with spermatozoa obtained from testicle biopsy. Hum Reprod 1995; 10:148.
  34. Silber SJ, Nagy Z, Liu J, et al. The use of epididymal and testicular spermatozoa for intracytoplasmic sperm injection: the genetic implications for male infertility. Hum Reprod 1995; 10:2031.
  35. Watkins W, Nieto F, Bourne H, et al. Testicular and epididymal sperm in a microinjection program: methods of retrieval and results. Fertil Steril 1997; 67:527.
  36. Schiff JD, Palermo GD, Veeck LL, et al. Success of testicular sperm extraction [corrected] and intracytoplasmic sperm injection in men with Klinefelter syndrome. J Clin Endocrinol Metab 2005; 90:6263.
  37. Schlegel PN. Nonobstructive azoospermia: a revolutionary surgical approach and results. Semin Reprod Med 2009; 27:165.
  38. Ramasamy R, Ricci JA, Palermo GD, et al. Successful fertility treatment for Klinefelter's syndrome. J Urol 2009; 182:1108.
  39. Van Perperstraten AM, Proctor ML, Phillipson G, Johnson NP. Techniques for surgical retrieval of sperm prior to ICSI for azoospermia. Cochrane Database Syst Rev 2001; :CD002807.
  40. Nicopoullos JD, Gilling-Smith C, Almeida PA, et al. Use of surgical sperm retrieval in azoospermic men: a meta-analysis. Fertil Steril 2004; 82:691.
  41. Manning M, Jünemann KP, Alken P. Decrease in testosterone blood concentrations after testicular sperm extraction for intracytoplasmic sperm injection in azoospermic men. Lancet 1998; 352:37.
  42. Fischer R, Baukloh V, Naether OG, et al. Pregnancy after intracytoplasmic sperm injection of spermatozoa extracted from frozen-thawed testicular biopsy. Hum Reprod 1996; 11:2197.
  43. Cohen J, Garrisi GJ, Congedo-Ferrara TA, et al. Cryopreservation of single human spermatozoa. Hum Reprod 1997; 12:994.
  44. Ohlander S, Hotaling J, Kirshenbaum E, et al. Impact of fresh versus cryopreserved testicular sperm upon intracytoplasmic sperm injection pregnancy outcomes in men with azoospermia due to spermatogenic dysfunction: a meta-analysis. Fertil Steril 2014; 101:344.
  45. De Croo I, Van der Elst J, Everaert K, et al. Fertilization, pregnancy and embryo implantation rates after ICSI in cases of obstructive and non-obstructive azoospermia. Hum Reprod 2000; 15:1383.
  46. Vernaeve V, Tournaye H, Osmanagaoglu K, et al. Intracytoplasmic sperm injection with testicular spermatozoa is less successful in men with nonobstructive azoospermia than in men with obstructive azoospermia. Fertil Steril 2003; 79:529.
  47. Serkiz IaI, Kovtun TV, Riabova EZ, Chebotarev EE. [Chemoluminescence of the blood plasma alpha-and beta-lipoproteins in rats irradiated with fast neutrons]. Radiobiologiia 1977; 17:803.
  48. McVicar CM, O'Neill DA, McClure N, et al. Effects of vasectomy on spermatogenesis and fertility outcome after testicular sperm extraction combined with ICSI. Hum Reprod 2005; 20:2795.
  49. Abdelmassih V, Balmaceda JP, Tesarik J, et al. Relationship between time period after vasectomy and the reproductive capacity of sperm obtained by epididymal aspiration. Hum Reprod 2002; 17:736.
  50. Borges Júnior E, Rossi-Ferragut LM, Pasqualotto FF, et al. Different intervals between vasectomy and sperm retrieval interfere in the reproductive capacity from vasectomized men. J Assist Reprod Genet 2003; 20:33.
  51. Sakkas, AD, Manicardi, G, Bizarro, D, Bianchi, PG. Possible consequences of performing ICSI with sperm possessing nuclear DNA damage. Hum Fertil 2000; 26:3.
  52. Nagy ZP, Liu J, Joris H, et al. The result of intracytoplasmic sperm injection is not related to any of the three basic sperm parameters. Hum Reprod 1995; 10:1123.
  53. Liu J, Nagy Z, Joris H, et al. Analysis of 76 total fertilization failure cycles out of 2732 intracytoplasmic sperm injection cycles. Hum Reprod 1995; 10:2630.
  54. Sherins RJ, Thorsell LP, Dorfmann A, et al. Intracytoplasmic sperm injection facilitates fertilization even in the most severe forms of male infertility: pregnancy outcome correlates with maternal age and number of eggs available. Fertil Steril 1995; 64:369.
  55. Nagy ZP, Verheyen G, Tournaye H, Van Steirteghem AC. Special applications of intracytoplasmic sperm injection: the influence of sperm count, motility, morphology, source and sperm antibody on the outcome of ICSI. Hum Reprod 1998; 13 Suppl 1:143.
  56. Sathananthan, AH. The paternal centrosome: its role in human embryonic development and infertility (a recent discovery), in Current Issues in Obstetrics and Gynaecology, Arulkumaran S and Ng SC, Eds, Oxford University Press, Singapore 1996. p.101.
  57. Sathananthan, AH, Trounson, A. Ultrastructure of ICSI. In: Handbook of in vitro Fertilization, 2nd ed, Trounson, AO, Gardner, DK, (Eds), CRC Press 2000.
  58. Ord T, Patrizio P, Marello E, et al. Mini-Percoll: a new method of semen preparation for IVF in severe male factor infertility. Hum Reprod 1990; 5:987.
  59. Tournaye H, Janssens R, Verheyen G, et al. In vitro fertilization in couples with previous fertilization failure using sperm incubated with pentoxifylline and 2-deoxyadenosine. Fertil Steril 1994; 62:574.
  60. Liu J, Tsai YL, Katz E, et al. High fertilization rate obtained after intracytoplasmic sperm injection with 100% nonmotile spermatozoa selected by using a simple modified hypo-osmotic swelling test. Fertil Steril 1997; 68:373.
  61. El-Nour AM, Al Mayman HA, Jaroudi KA, Coskun S. Effects of the hypo-osmotic swelling test on the outcome of intracytoplasmic sperm injection for patients with only nonmotile spermatozoa available for injection: a prospective randomized trial. Fertil Steril 2001; 75:480.
  62. Morris ID, Ilott S, Dixon L, Brison DR. The spectrum of DNA damage in human sperm assessed by single cell gel electrophoresis (Comet assay) and its relationship to fertilization and embryo development. Hum Reprod 2002; 17:990.
  63. Sakkas D, Manicardi GC, Tomlinson M, et al. The use of two density gradient centrifugation techniques and the swim-up method to separate spermatozoa with chromatin and nuclear DNA anomalies. Hum Reprod 2000; 15:1112.
  64. Muriel L, Garrido N, Fernández JL, et al. Value of the sperm deoxyribonucleic acid fragmentation level, as measured by the sperm chromatin dispersion test, in the outcome of in vitro fertilization and intracytoplasmic sperm injection. Fertil Steril 2006; 85:371.
  65. Bartoov B, Berkovitz A, Eltes F. Selection of spermatozoa with normal nuclei to improve the pregnancy rate with intracytoplasmic sperm injection. N Engl J Med 2001; 345:1067.
  66. Nicopoullos JD, Gilling-Smith C, Almeida PA, et al. The role of sperm aneuploidy as a predictor of the success of intracytoplasmic sperm injection? Hum Reprod 2008; 23:240.
  67. Jakab A, Sakkas D, Delpiano E, et al. Intracytoplasmic sperm injection: a novel selection method for sperm with normal frequency of chromosomal aneuploidies. Fertil Steril 2005; 84:1665.
  68. McDowell S, Kroon B, Ford E, et al. Advanced sperm selection techniques for assisted reproduction. Cochrane Database Syst Rev 2014; :CD010461.
  69. Katz E, Watts LD, Wright KE, et al. Effect of incremental time experience on the results of in vitro fertilization with intracytoplasmic sperm injection (ICSI). J Assist Reprod Genet 1996; 13:501.
  70. Wang WH, Meng L, Hackett RJ, et al. Limited recovery of meiotic spindles in living human oocytes after cooling-rewarming observed using polarized light microscopy. Hum Reprod 2001; 16:2374.
  71. Wang WH, Meng L, Hackett RJ, et al. The spindle observation and its relationship with fertilization after intracytoplasmic sperm injection in living human oocytes. Fertil Steril 2001; 75:348.
  72. Wang WH, Meng L, Hackett RJ, et al. Rigorous thermal control during intracytoplasmic sperm injection stabilizes the meiotic spindle and improves fertilization and pregnancy rates. Fertil Steril 2002; 77:1274.
  73. Malter, HE. Tools and techniques for embryological manipulation. In: Micromanipulation of Human Gametes and Embryos, Cohen, J, Malter, HE, Talansky, BE, et al (Eds), Raven Press, New York 1992. p.250.
  74. Schiewe MC. An effective, simplified, and practical approach to intracytoplasmic sperm injection at multiple IVF centers. J Assist Reprod Genet 1996; 13:238.
  75. Johnson, CA, Boldt, J. Assisted Reproduction: Laboratory Consideration. In: Infertility and Reproductive Medicine Clinics of North America, Vol 9, Diamond, MP, DeCherney, AH (Eds), 1998. p.205.
  76. Oehninger S, Veeck L, Lanzendorf S, et al. Intracytoplasmic sperm injection: achievement of high pregnancy rates in couples with severe male factor infertility is dependent primarily upon female and not male factors. Fertil Steril 1995; 64:977.
  77. Devroey P, Godoy H, Smitz J, et al. Female age predicts embryonic implantation after ICSI: a case-controlled study. Hum Reprod 1996; 11:1324.
  78. Alikani M, Palermo G, Adler A, et al. Intracytoplasmic sperm injection in dysmorphic human oocytes. Zygote 1995; 3:283.
  79. Greenblatt EM, Meriano JS, Casper RF. Type of stimulation protocol affects oocyte maturity, fertilization rate, and cleavage rate after intracytoplasmic sperm injection. Fertil Steril 1995; 64:557.
  80. Palermo GD, Alikani M, Bertoli M, et al. Oolemma characteristics in relation to survival and fertilization patterns of oocytes treated by intracytoplasmic sperm injection. Hum Reprod 1996; 11:172.
  81. Graham CF. Parthenogenetic mouse blastocysts. Nature 1970; 226:165.
  82. Palermo G, Joris H, Derde MP, et al. Sperm characteristics and outcome of human assisted fertilization by subzonal insemination and intracytoplasmic sperm injection. Fertil Steril 1993; 59:826.
  83. Blake M, Garrisi J, Tomkin G, Cohen J. Sperm deposition site during ICSI affects fertilization and development. Fertil Steril 2000; 73:31.
  84. Nagy ZP, Liu J, Joris H, et al. The influence of the site of sperm deposition and mode of oolemma breakage at intracytoplasmic sperm injection on fertilization and embryo development rates. Hum Reprod 1995; 10:3171.
  85. Tesarik J, Sousa M. Key elements of a highly efficient intracytoplasmic sperm injection technique: Ca2+ fluxes and oocyte cytoplasmic dislocation. Fertil Steril 1995; 64:770.
  86. Dumoulin JM, Coonen E, Bras M, et al. Embryo development and chromosomal anomalies after ICSI: effect of the injection procedure. Hum Reprod 2001; 16:306.
  87. Demirol A, Benkhalifa M, Sari T, Gurgan T. Use of laser-assisted intracytoplasmic sperm injection (ICSI) in patients with a history of poor ICSI outcome and limited metaphase II oocytes. Fertil Steril 2006; 86:256.
  88. Huang H, Mills JK, Lu C, Sun D. A universal piezo-driven ultrasonic cell microinjection system. Biomed Microdevices 2011; 13:743.
  89. American Society for Reproductive Medicine., Intracystoplasmic sperm injection. (www.asrm.org/Patients/FactSheets/ICSI-Fact.pdf (Accessed 3/7/05)).
  90. Dozortsev D, De Sutter P, Dhont M. Behaviour of spermatozoa in human oocytes displaying no or one pronucleus after intracytoplasmic sperm injection. Hum Reprod 1994; 9:2139.
  91. Schmiady H, Tandler-Schneider A, Kentenich H. Premature chromosome condensation of the sperm nucleus after intracytoplasmic sperm injection. Hum Reprod 1996; 11:2239.
  92. Rienzi L, Ubaldi F, Anniballo R, et al. Preincubation of human oocytes may improve fertilization and embryo quality after intracytoplasmic sperm injection. Hum Reprod 1998; 13:1014.
  93. Ebner T, Moser M, Sommergruber M, et al. Complete oocyte activation failure after ICSI can be overcome by a modified injection technique. Hum Reprod 2004; 19:1837.
  94. Heindryckx B, Van der Elst J, De Sutter P, Dhont M. Treatment option for sperm- or oocyte-related fertilization failure: assisted oocyte activation following diagnostic heterologous ICSI. Hum Reprod 2005; 20:2237.
  95. Swain JE, Pool TB. ART failure: oocyte contributions to unsuccessful fertilization. Hum Reprod Update 2008; 14:431.
  96. Liu J, Nagy Z, Joris H, et al. Successful fertilization and establishment of pregnancies after intracytoplasmic sperm injection in patients with globozoospermia. Hum Reprod 1995; 10:626.
  97. Nagy ZP, Liu J, Joris H, et al. Time-course of oocyte activation, pronucleus formation and cleavage in human oocytes fertilized by intracytoplasmic sperm injection. Hum Reprod 1994; 9:1743.
  98. Nagy ZP, Janssenswillen C, Janssens R, et al. Timing of oocyte activation, pronucleus formation and cleavage in humans after intracytoplasmic sperm injection (ICSI) with testicular spermatozoa and after ICSI or in-vitro fertilization on sibling oocytes with ejaculated spermatozoa. Hum Reprod 1998; 13:1606.
  99. Palermo G, Munné S, Cohen J. The human zygote inherits its mitotic potential from the male gamete. Hum Reprod 1994; 9:1220.
  100. Flaherty SP, Payne D, Swann NJ, Mattews CD. Aetiology of failed and abnormal fertilization after intracytoplasmic sperm injection. Hum Reprod 1995; 10:2623.
  101. Sultan KM, Munné S, Palermo GD, et al. Chromosomal status of uni-pronuclear human zygotes following in-vitro fertilization and intracytoplasmic sperm injection. Hum Reprod 1995; 10:132.
  102. Oehninger S, Kruger TF, Simon T, et al. A comparative analysis of embryo implantation potential in patients with severe teratozoospermia undergoing in-vitro fertilization with a high insemination concentration or intracytoplasmic sperm injection. Hum Reprod 1996; 11:1086.
  103. Yang D, Shahata MA, al-Bader M, et al. Intracytoplasmic sperm injection improving embryo quality: comparison of the sibling oocytes of non-male-factor couples. J Assist Reprod Genet 1996; 13:351.
  104. Griffiths TA, Murdoch AP, Herbert M. Embryonic development in vitro is compromised by the ICSI procedure. Hum Reprod 2000; 15:1592.
  105. Shoukir Y, Chardonnens D, Campana A, Sakkas D. Blastocyst development from supernumerary embryos after intracytoplasmic sperm injection: a paternal influence? Hum Reprod 1998; 13:1632.
  106. Dumoulin JC, Coonen E, Bras M, et al. Comparison of in-vitro development of embryos originating from either conventional in-vitro fertilization or intracytoplasmic sperm injection. Hum Reprod 2000; 15:402.
  107. Janny L, Menezo YJ. Evidence for a strong paternal effect on human preimplantation embryo development and blastocyst formation. Mol Reprod Dev 1994; 38:36.
  108. Jones GM, Trounson AO, Lolatgis N, Wood C. Factors affecting the success of human blastocyst development and pregnancy following in vitro fertilization and embryo transfer. Fertil Steril 1998; 70:1022.
  109. Miller JE, Smith TT. The effect of intracytoplasmic sperm injection and semen parameters on blastocyst development in vitro. Hum Reprod 2001; 16:918.
  110. Schoolcraft WB, Gardner DK, Lane M, et al. Blastocyst culture and transfer: analysis of results and parameters affecting outcome in two in vitro fertilization programs. Fertil Steril 1999; 72:604.
  111. Cohen J, Simons RS, Fehilly CB, Edwards RG. Factors affecting survival and implantation of cryopreserved human embryos. J In Vitro Fert Embryo Transf 1986; 3:46.
  112. Schnorr J, Brown S, Oehninger S, et al. Impact of intracytoplasmic sperm injection on embryo cryopreservation and clinical outcome. Fertil Steril 2001; 75:636.
  113. Macas E, Imthurn B, Borsos M, et al. Impairment of the developmental potential of frozen-thawed human zygotes obtained after intracytoplasmic sperm injection. Fertil Steril 1998; 69:630.
  114. Van Steirteghem AC, Van der Elst J, Van den Abbeel E, et al. Cryopreservation of supernumerary multicellular human embryos obtained after intracytoplasmic sperm injection. Fertil Steril 1994; 62:775.
  115. Damario MA, Hammitt DG, Galanits TM, et al. Pronuclear stage cryopreservation after intracytoplasmic sperm injection and conventional IVF: implications for timing of the freeze. Fertil Steril 1999; 72:1049.
  116. Kowalik A, Palermo GD, Barmat L, et al. Comparison of clinical outcome after cryopreservation of embryos obtained from intracytoplasmic sperm injection and in-vitro fertilization. Hum Reprod 1998; 13:2848.
  117. Belva F, Henriet S, Van den Abbeel E, et al. Neonatal outcome of 937 children born after transfer of cryopreserved embryos obtained by ICSI and IVF and comparison with outcome data of fresh ICSI and IVF cycles. Hum Reprod 2008; 23:2227.
  118. de Cássia Savio Figueira R, Madaschi C, Nichi M, et al. A comparison of post-thaw results between embryos arising from intracytoplasmic sperm injection using surgically retrieved or ejaculated spermatozoa. Fertil Steril 2009; 91:727.
  119. Bonduelle M, Van Assche E, Joris H, et al. Prenatal testing in ICSI pregnancies: incidence of chromosomal anomalies in 1586 karyotypes and relation to sperm parameters. Hum Reprod 2002; 17:2600.
  120. van Rumste MM, Evers JL, Farquhar CM. Intra-cytoplasmic sperm injection versus conventional techniques for oocyte insemination during in vitro fertilisation in patients with non-male subfertility. Cochrane Database Syst Rev 2003; :CD001301.
  121. Bonduelle M, Wennerholm UB, Loft A, et al. A multi-centre cohort study of the physical health of 5-year-old children conceived after intracytoplasmic sperm injection, in vitro fertilization and natural conception. Hum Reprod 2005; 20:413.
  122. Society for Assisted Reproductive Technology, American Society for Reproductive Medicine. Assisted reproductive technology in the United States: 2001 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology registry. Fertil Steril 2007; 87:1253.
  123. Bonduelle M, Legein J, Buysse A, et al. Prospective follow-up study of 423 children born after intracytoplasmic sperm injection. Hum Reprod 1996; 11:1558.
  124. www.cdc.gov. (accessed April 22, 2009).
  125. Abusheikha N, Salha O, Sharma V, Brinsden P. Monozygotic twinning and IVF/ICSI treatment: a report of 11 cases and review of literature. Hum Reprod Update 2000; 6:396.
  126. Tarlatzis BC, Qublan HS, Sanopoulou T, et al. Increase in the monozygotic twinning rate after intracytoplasmic sperm injection and blastocyst stage embryo transfer. Fertil Steril 2002; 77:196.
  127. Skiadas CC, Missmer SA, Benson CB, et al. Risk factors associated with pregnancies containing a monochorionic pair following assisted reproductive technologies. Hum Reprod 2008; 23:1366.
  128. Yoon G, Beischel LS, Johnson JP, Jones MC. Dizygotic twin pregnancy conceived with assisted reproductive technology associated with chromosomal anomaly, imprinting disorder, and monochorionic placentation. J Pediatr 2005; 146:565.
  129. Souter VL, Kapur RP, Nyholt DR, et al. A report of dizygous monochorionic twins. N Engl J Med 2003; 349:154.
  130. Belva F, Roelants M, Vloeberghs V, et al. Serum reproductive hormone levels and ultrasound findings in female offspring after intracytoplasmic sperm injection: first results. Fertil Steril 2017; 107:934.
  131. Belva F, Henriet S, Liebaers I, et al. Medical outcome of 8-year-old singleton ICSI children (born >or=32 weeks' gestation) and a spontaneously conceived comparison group. Hum Reprod 2007; 22:506.
  132. Leunens L, Celestin-Westreich S, Bonduelle M, et al. Follow-up of cognitive and motor development of 10-year-old singleton children born after ICSI compared with spontaneously conceived children. Hum Reprod 2008; 23:105.
  133. Ludwig AK, Katalinic A, Thyen U, et al. Physical health at 5.5 years of age of term-born singletons after intracytoplasmic sperm injection: results of a prospective, controlled, single-blinded study. Fertil Steril 2009; 91:115.
  134. Ludwig A, Katalinic A, Thyen U, et al. Neuromotor development and mental health at 5.5 years of age of singletons born at term after intracytoplasmatic sperm injection ICSI: results of a prospective controlled single-blinded study in Germany. Fertil Steril 2009; 91:125.
  135. Katalinic A, Rösch C, Ludwig M, German ICSI Follow-Up Study Group. Pregnancy course and outcome after intracytoplasmic sperm injection: a controlled, prospective cohort study. Fertil Steril 2004; 81:1604.
  136. Fedder J, Loft A, Parner ET, et al. Neonatal outcome and congenital malformations in children born after ICSI with testicular or epididymal sperm: a controlled national cohort study. Hum Reprod 2013; 28:230.
  137. Practice Committee of American Society for Reproductive Medicine, Practice Committee of Society for Assisted Reproductive Technology. Genetic considerations related to intracytoplasmic sperm injection (ICSI). Fertil Steril 2008; 90:S182.
  138. Gosden R, Trasler J, Lucifero D, Faddy M. Rare congenital disorders, imprinted genes, and assisted reproductive technology. Lancet 2003; 361:1975.
  139. Nikolettos N, Asimakopoulos B, Papastefanou IS. Intracytoplasmic sperm injection--an assisted reproduction technique that should make us cautious about imprinting deregulation. J Soc Gynecol Investig 2006; 13:317.
  140. Ørstavik KH, Eiklid K, van der Hagen CB, et al. Another case of imprinting defect in a girl with Angelman syndrome who was conceived by intracytoplasmic semen injection. Am J Hum Genet 2003; 72:218.
  141. Cox GF, Bürger J, Lip V, et al. Intracytoplasmic sperm injection may increase the risk of imprinting defects. Am J Hum Genet 2002; 71:162.
  142. Chang PL, Sauer MV, Brown S. Y chromosome microdeletion in a father and his four infertile sons. Hum Reprod 1999; 14:2689.
  143. Wennerholm UB, Bergh C, Hamberger L, et al. Incidence of congenital malformations in children born after ICSI. Hum Reprod 2000; 15:944.
  144. American College of Obstetricians and Gynecologists’ Committee on Obstetric Practice, Committee on Genetics, U.S. Food and Drug Administration. Committee Opinion No 671: Perinatal Risks Associated With Assisted Reproductive Technology. Obstet Gynecol 2016; 128:e61.
  145. Gekas J, Thepot F, Turleau C, et al. Chromosomal factors of infertility in candidate couples for ICSI: an equal risk of constitutional aberrations in women and men. Hum Reprod 2001; 16:82.
  146. Foresta C, Garolla A, Bartoloni L, et al. Genetic abnormalities among severely oligospermic men who are candidates for intracytoplasmic sperm injection. J Clin Endocrinol Metab 2005; 90:152.
  147. Woldringh GH, Janssen IM, Hehir-Kwa JY, et al. Constitutional DNA copy number changes in ICSI children. Hum Reprod 2009; 24:233.
  148. Martin RH. Cytogenetic determinants of male fertility. Hum Reprod Update 2008; 14:379.
  149. Ohashi Y, Miharu N, Honda H, et al. High frequency of XY disomy in spermatozoa of severe oligozoospermic men. Hum Reprod 2001; 16:703.
  150. Pang MG, Kim YJ, Lee SH, Kim CK. The high incidence of meiotic errors increases with decreased sperm count in severe male factor infertilities. Hum Reprod 2005; 20:1688.
  151. ACOG Committee on Obstetric Practice, ACOG Committee on Gynecologic Practice, ACOG Committee on Genetics. ACOG Committee Opinion #324: Perinatal risks associated with assisted reproductive technology. Obstet Gynecol 2005; 106:1143.
  152. Bonduelle M, Liebaers I, Deketelaere V, et al. Neonatal data on a cohort of 2889 infants born after ICSI (1991-1999) and of 2995 infants born after IVF (1983-1999). Hum Reprod 2002; 17:671.
  153. Belva F, De Schrijver F, Tournaye H, et al. Neonatal outcome of 724 children born after ICSI using non-ejaculated sperm. Hum Reprod 2011; 26:1752.
  154. Belva F, Roelants M, De Schepper J, et al. Reproductive hormones of ICSI-conceived young adult men: the first results. Hum Reprod 2017; 32:439.
  155. Belva F, Bonduelle M, Roelants M, et al. Semen quality of young adult ICSI offspring: the first results. Hum Reprod 2016; 31:2811.