Why we should transfer frozen instead of fresh embryos: The translational rationale

Fertility and Sterility

Volumn 102, Issue 1, 2014, Pages 10-18

  Weinerman, Rachel ^a   Mainigi, Monica ^a  

^a UNIVERSITY OF PENNSYLVANIA   (United States)

Author keywords

frozen embryo transfer; implantation; In vitro fertilization; placentation; superovulation

Indexed keywords

ESTRADIOL; GONADOTROPIN; PROGESTERONE; VASCULOTROPIN;

ADVERSE OUTCOME; CORPUS LUTEUM; EMBRYO DEVELOPMENT; EMBRYO TRANSFER; ENDOMETRIAL RECEPTIVITY; ENDOMETRIUM; ENVIRONMENT; EPIGENETICS; FERTILIZATION IN VITRO; FETUS GROWTH; FROZEN EMBRYO TRANSFER; GENE; GENE EXPRESSION; HORMONE RELEASE; HUMAN; META ANALYSIS (TOPIC); NATURAL KILLER CELL; NIDATION; NONHUMAN; OOCYTE; PERINATAL PERIOD; PLACENTA DEVELOPMENT; PRIORITY JOURNAL; REVIEW; SMALL FOR DATE INFANT; STC1 GENE; SUPEROVULATION; UTERUS FUNCTION;

FROZEN EMBRYO TRANSFER; IMPLANTATION; IN VITRO FERTILIZATION; PLACENTATION; SUPEROVULATION;

ANIMALS; CRYOPRESERVATION; EMBRYO IMPLANTATION; EMBRYO TRANSFER; EMBRYO, MAMMALIAN; ENDOMETRIUM; FEMALE; FERTILITY; FERTILITY AGENTS, FEMALE; FERTILIZATION IN VITRO; HUMANS; INFERTILITY; OVULATION INDUCTION; PREGNANCY; PREGNANCY RATE; RISK ASSESSMENT; RISK FACTORS; SUPEROVULATION; TIME FACTORS; TRANSLATIONAL MEDICAL RESEARCH; TREATMENT OUTCOME;

EID: 84903383469     PISSN: 00150282     EISSN: 15565653     Source Type: Journal    
DOI: 10.1016/j.fertnstert.2014.05.019     Document Type: Review

References (92)

1. S.K. Kalra, and K.T. Barnhart In vitro fertilization and adverse childhood outcomes: what we know, where we are going, and how we will get there. A glimpse into what lies behind and beckons ahead Fertil Steril 95 2011 1887 1889
2. A. Pinborg, U.B. Wennerholm, L.B. Romundstad, A. Loft, K. Aittomaki, and V. Soderstrom-Anttila et al. Why do singletons conceived after assisted reproduction technology have adverse perinatal outcome? Systematic review and meta-Analysis Hum Reprod Update 19 2013 87 104
3. K. Chung, C. Coutifaris, R. Chalian, K. Lin, S.J. Ratcliffe, and A.J. Castelbaum et al. Factors influencing adverse perinatal outcomes in pregnancies achieved through use of in vitro fertilization Fertil Steril 86 2006 1634 1641
4. A.K. Henningsen, A. Pinborg, O. Lidegaard, C. Vestergaard, J.L. Forman, and A.N. Andersen Perinatal outcome of singleton siblings born after assisted reproductive technology and spontaneous conception: Danish national sibling-cohort study Fertil Steril 95 2011 959 963
5. S.K. Kalra, S.J. Ratcliffe, C. Coutifaris, T. Molinaro, and K.T. Barnhart Ovarian stimulation and low birth weight in newborns conceived through in vitro fertilization Obstet Gynecol 118 2011 863 871
6. P. Hovi, S. Andersson, J.G. Eriksson, A.L. Jarvenpaa, S. Strang-Karlsson, and O. Makitie et al. Glucose regulation in young adults with very low birth weight N Engl J Med 356 2007 2053 2063
7. E. Kajantie, and P. Hovi Is very preterm birth a risk factor for adult cardiometabolic disease? Semin Fetal Neonat Med 19 2014 112 117
8. A. Eroglu, and L.C. Layman Role of ART in imprinting disorders Semin Reprod Med 30 2012 92 104
9. M.M. Denomme, and M.R. Mann Genomic imprints as a model for the analysis of epigenetic stability during assisted reproductive technologies Reproduction 144 2012 393 409
10. S.K. Feuer, L. Camarano, and P.F. Rinaudo ART and health: clinical outcomes and insights on molecular mechanisms from rodent studies Mol Hum Reprod 19 2013 189 204
11. M.A. Santos, E.W. Kuijk, and N.S. Macklon The impact of ovarian stimulation for IVF on the developing embryo Reproduction 139 2010 23 34
12. B.S. Shapiro, S.T. Daneshmand, F.C. Garner, M. Aguirre, C. Hudson, and S. Thomas Evidence of impaired endometrial receptivity after ovarian stimulation for in vitro fertilization: A prospective randomized trial comparing fresh and frozen-thawed embryo transfer in normal responders Fertil Steril 96 2011 344 348
13. B.S. Shapiro, S.T. Daneshmand, H. Restrepo, F.C. Garner, M. Aguirre, and C. Hudson Matched-cohort comparison of single-embryo transfers in fresh and frozen-thawed embryo transfer cycles Fertil Steril 99 2013 389 392
14. M. Roque, K. Lattes, S. Serra, I. Sola, S. Geber, and R. Carreras et al. Fresh embryo transfer versus frozen embryo transfer in in vitro fertilization cycles: A systematic review and meta-Analysis Fertil Steril 99 2013 156 162
15. S. Kansal Kalra, S.J. Ratcliffe, L. Milman, C.R. Gracia, C. Coutifaris, and K.T. Barnhart Perinatal morbidity after in vitro fertilization is lower with frozen embryo transfer Fertil Steril 95 2011 548 553
16. O. Kato, N. Kawasaki, D. Bodri, T. Kuroda, S. Kawachiya, and K. Kato et al. Neonatal outcome and birth defects in 6623 singletons born following minimal ovarian stimulation and vitrified versus fresh single embryo transfer Eur J Obstet Gynecol Reprod Biol 161 2012 46 50
17. S.Y. Liu, B. Teng, J. Fu, X. Li, Y. Zheng, and X.X. Sun Obstetric and neonatal outcomes after transfer of vitrified early cleavage embryos Hum Reprod 28 2013 2093 2100
18. A. Maheshwari, S. Pandey, A. Shetty, M. Hamilton, and S. Bhattacharya Obstetric and perinatal outcomes in singleton pregnancies resulting from the transfer of frozen thawed versus fresh embryos generated through in vitro fertilization treatment: A systematic review and meta-Analysis Fertil Steril 98 2012 368 377 e1-9
19. S. Pelkonen, R. Koivunen, M. Gissler, S. Nuojua-Huttunen, A.M. Suikkari, and C. Hyden-Granskog et al. Perinatal outcome of children born after frozen and fresh embryo transfer: The Finnish cohort study 1995-2006 Hum Reprod 25 2010 914 923
20. A. Pinborg, A. Loft, A.K. Aaris Henningsen, S. Rasmussen, and A.N. Andersen Infant outcome of 957 singletons born after frozen embryo replacement: The Danish National Cohort Study 1995-2006 Fertil Steril 94 2010 1320 1327
21. M. Wikland, T. Hardarson, T. Hillensjo, C. Westin, G. Westlander, and M. Wood et al. Obstetric outcomes after transfer of vitrified blastocysts Hum Reprod 25 2010 1699 1707
22. U.B. Wennerholm, A.K. Henningsen, L.B. Romundstad, C. Bergh, A. Pinborg, and R. Skjaerven et al. Perinatal outcomes of children born after frozen-thawed embryo transfer: A Nordic cohort study from the CONARTAS group Hum Reprod 28 2013 2545 2553
23. O. Ishihara, R. Araki, A. Kuwahara, A. Itakura, H. Saito, and G.D. Adamson Impact of frozen-thawed single-blastocyst transfer on maternal and neonatal outcome: An analysis of 277,042 single-embryo transfer cycles from 2008 to 2010 in Japan Fertil Steril 101 2014 128 133
24. J. Farhi, A. Ben-Haroush, N. Andrawus, H. Pinkas, O. Sapir, and B. Fisch et al. High serum oestradiol concentrations in IVF cycles increase the risk of pregnancy complications related to abnormal placentation Reprod Biomed Online 21 2010 331 337
25. B.S. Joo, S.H. Park, B.M. An, K.S. Kim, S.E. Moon, and H.S. Moon Serum estradiol levels during controlled ovarian hyperstimulation influence the pregnancy outcome of in vitro fertilization in a concentration-dependent manner Fertil Steril 93 2010 442 446
26. A.N. Imudia, A.O. Awonuga, A.J. Kaimal, D.L. Wright, A.K. Styer, and T.L. Toth Elective cryopreservation of all embryos with subsequent cryothaw embryo transfer in patients at risk for ovarian hyperstimulation syndrome reduces the risk of adverse obstetric outcomes: A preliminary study Fertil Steril 99 2013 168 173
27. A.N. Imudia, A.O. Awonuga, J.O. Doyle, A.J. Kaimal, D.L. Wright, and T.L. Toth et al. Peak serum estradiol level during controlled ovarian hyperstimulation is associated with increased risk of small for gestational age and preeclampsia in singleton pregnancies after in vitro fertilization Fertil Steril 97 2012 1374 1379
28. A. Dursun, F. Sendag, M.C. Terek, H. Yilmaz, K. Oztekin, and M. Baka et al. Morphometric changes in the endometrium and serum leptin levels during the implantation period of the embryo in the rat in response to exogenous ovarian stimulation Fertil Steril 82 Suppl 3 2004 1121 1126
29. B. Kramer, B.A. Stein, and L.A. van der Walt Exogenous gonadotropins - serum oestrogen and progesterone and the effect on endometrial morphology in the rat J Anat 173 1990 177 186
30. F. Sendag, A. Akdogan, K. Ozbilgin, G. Giray, and K. Oztekin Effect of ovarian stimulation with human menopausal gonadotropin and recombinant follicle stimulating hormone on the expression of integrins alpha3, beta1 in the rat endometrium during the implantation period Eur J Obstet Gynecol Reprod Biol 150 2010 57 60
31. W.R. Meyer, D.B. Novotny, M.A. Fritz, S.A. Beyler, L.J. Wolf, and B.A. Lessey Effect of exogenous gonadotropins on endometrial maturation in oocyte donors Fertil Steril 71 1999 109 114
32. A.J. Wilcox, D.D. Baird, and C.R. Weinberg Time of implantation of the conceptus and loss of pregnancy N Engl J Med 340 1999 1796 1799
33. E.R. Norwitz, D.J. Schust, and S.J. Fisher Implantation and the survival of early pregnancy N Engl J Med 345 2001 1400 1408
34. A. Lass, D. Peat, S. Avery, and P. Brinsden Histological evaluation of endometrium on the day of oocyte retrieval after gonadotrophin-releasing hormone agonist-follicle stimulating hormone ovulation induction for in-vitro fertilization Hum Reprod 13 1998 3203 3205
35. F. Ubaldi, C. Bourgain, H. Tournaye, J. Smitz, A. van Steirteghem, and P. Devroey Endometrial evaluation by aspiration biopsy on the day of oocyte retrieval in the embryo transfer cycles in patients with serum progesterone rise during the follicular phase Fertil Steril 67 1997 521 526
36. G. Zapantis, M.J. Szmyga, E.A. Rybak, and U.T. Meier Premature formation of nucleolar channel systems indicates advanced endometrial maturation following controlled ovarian hyperstimulation Hum Reprod 28 2013 3292 3300
37. J. Cha, X. Sun, and S.K. Dey Mechanisms of implantation: strategies for successful pregnancy Nat Med 18 2012 1754 1767
38. E. Bosch, E. Labarta, J. Crespo, C. Simon, J. Remohi, and J. Jenkins et al. Circulating progesterone levels and ongoing pregnancy rates in controlled ovarian stimulation cycles for in vitro fertilization: Analysis of over 4000 cycles Hum Reprod 25 2010 2092 2100
39. E.M. Kolibianakis, C.A. Venetis, J. Bontis, and B.C. Tarlatzis Significantly lower pregnancy rates in the presence of progesterone elevation in patients treated with GnRH antagonists and gonadotrophins: A systematic review and meta-Analysis Curr Pharmaceut Biotechnol 13 2012 464 470
40. H.M. Fatemi, and B. Popovic-Todorovic Implantation in assisted reproduction: A look at endometrial receptivity Reprod Biomed Online 27 2013 530 538
41. D. Kyrou, B. Popovic-Todorovic, H.M. Fatemi, C. Bourgain, P. Haentjens, and L. van Landuyt et al. Does the estradiol level on the day of human chorionic gonadotrophin administration have an impact on pregnancy rates in patients treated with rec-FSH/GnRH antagonist? Hum Reprod 24 2009 2902 2909
42. M. Al-Azemi, D. Kyrou, E.M. Kolibianakis, P. Humaidan, I. van Vaerenbergh, and P. Devroey et al. Elevated progesterone during ovarian stimulation for IVF Reprod Biomed Online 24 2012 381 388
43. B.S. Shapiro, S.T. Daneshmand, F.C. Garner, M. Aguirre, C. Hudson, and S. Thomas Embryo cryopreservation rescues cycles with premature luteinization Fertil Steril 93 2010 636 641
44. A.J. Polotsky, J.L. Daif, S. Jindal, H.J. Lieman, N. Santoro, and L. Pal Serum progesterone on the day of human chorionic gonadotropin administration predicts clinical pregnancy of sibling frozen embryos Fertil Steril 92 2009 1880 1885
45. S. Mirkin, G. Nikas, J.G. Hsiu, J. Diaz, and S. Oehninger Gene expression profiles and structural/functional features of the peri-implantation endometrium in natural and gonadotropin-stimulated cycles J Clin Endocrinol Metab 89 2004 5742 5752
46. J.A. Horcajadas, A. Riesewijk, J. Polman, R. van Os, A. Pellicer, and S. Mosselman et al. Effect of controlled ovarian hyperstimulation in IVF on endometrial gene expression profiles Mol Hum Reprod 11 2005 195 205
47. C. Simon, J. Oberye, J. Bellver, C. Vidal, E. Bosch, and J.A. Horcajadas et al. Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist or in natural cycles Hum Reprod 20 2005 3318 3327
48. J.A. Horcajadas, P. Minguez, J. Dopazo, F.J. Esteban, F. Dominguez, and L.C. Giudice et al. Controlled ovarian stimulation induces a functional genomic delay of the endometrium with potential clinical implications J Clin Endocrinol Metab 93 2008 4500 4510
49. Y. Liu, K.F. Lee, E.H. Ng, W.S. Yeung, and P.C. Ho Gene expression profiling of human peri-implantation endometria between natural and stimulated cycles Fertil Steril 90 2008 2152 2164
50. D. Haouzi, S. Assou, K. Mahmoud, S. Tondeur, T. Reme, and B. Hedon et al. Gene expression profile of human endometrial receptivity: comparison between natural and stimulated cycles for the same patients Hum Reprod 24 2009 1436 1445
51. R. Li, J. Qiao, L. Wang, L. Li, X. Zhen, and P. Liu et al. MicroRNA array and microarray evaluation of endometrial receptivity in patients with high serum progesterone levels on the day of hCG administration Reprod Biol Endocrinol 9 2011 29
52. M. Xiong, H. Zhang, L. Jin, J. Ai, Z. Huang, and G. Zhu Association of controlled ovarian hyperstimulation treatment with down-regulation of key regulators involved in embryonic implantation in mice J Huazhong Univ Sci Technolog Med Sci 31 2011 535 542
53. P. Humaidan, I. van Vaerenbergh, C. Bourgain, B. Alsbjerg, C. Blockeel, and F. Schuit et al. Endometrial gene expression in the early luteal phase is impacted by mode of triggering final oocyte maturation in recFSH stimulated and GnRH antagonist co-treated IVF cycles Hum Reprod 27 2012 3259 3272
54. J.Y. Lee, M. Lee, and S.K. Lee Role of endometrial immune cells in implantation Clin Exp Reprod Med 38 2011 119 125
55. L. Flynn, B. Byrne, J. Carton, P. Kelehan, C. O'Herlihy, and C. O'Farrelly Menstrual cycle dependent fluctuations in NK and T-lymphocyte subsets from nonpregnant human endometrium Am J Reprod Immunol 43 2000 209 217
56. N. Mariee, T.C. Li, and S.M. Laird Expression of leukaemia inhibitory factor and interleukin 15 in endometrium of women with recurrent implantation failure after IVF; correlation with the number of endometrial natural killer cells Hum Reprod 27 2012 1946 1954
57. P. Dorfeshan, M. Salehnia, and S.M. Moazzeni Ovarian stimulation affects the population of mouse uterine NK cells at early pregnancy Biomed Res Int 2013 2013 182531
58. G. Junovich, Y. Mayer, A. Azpiroz, S. Daher, A. Iglesias, and C. Zylverstein et al. Ovarian stimulation affects the levels of regulatory endometrial NK cells and angiogenic cytokine VEGF Am J Reprod Immunol 65 2011 146 153
59. G. Chaouat Inflammation, NK cells and implantation: friend and foe (the good, the bad and the ugly?): replacing placental viviparity in an evolutionary perspective J Reprod Immunol 97 2013 2 13
60. L. delle Piane, W. Lin, X. Liu, A. Donjacour, P. Minasi, and A. Revelli et al. Effect of the method of conception and embryo transfer procedure on mid-gestation placenta and fetal development in an IVF mouse model Hum Reprod 25 2010 2039 2046
61. E. Bloise, W. Lin, X. Liu, R. Simbulan, K.S. Kolahi, and F. Petraglia et al. Impaired placental nutrient transport in mice generated by in vitro fertilization Endocrinology 153 2012 3457 3467
62. S.K. Kalra Adverse perinatal outcome and in vitro fertilization singleton pregnancies: what lies beneath? Further evidence to support an underlying role of the modifiable hormonal milieu in in vitro fertilization stimulation Fertil Steril 97 2012 1295 1296
63. M.A. Mainigi, D. Olalere, I. Burd, C. Sapienza, M. Bartolomei, and C. Coutifaris Peri-implantation hormonal milieu: elucidating mechanisms of abnormal placentation and fetal growth Biol Reprod 90 2014 26
64. D. Lucifero, M.R. Mann, M.S. Bartolomei, and J.M. Trasler Gene-specific timing and epigenetic memory in oocyte imprinting Hum Mol Genet 13 2004 839 849
65. M.M. Denomme, and M.R. Mann Maternal control of genomic imprint maintenance Reprod Biomed Online 27 2013 629 636
66. H. Cedar, and Y. Bergman Programming of DNA methylation patterns Annu Rev Biochem 81 2012 97 117
67. B.A. Market-Velker, L. Zhang, L.S. Magri, A.C. Bonvissuto, and M.R. Mann Dual effects of superovulation: loss of maternal and paternal imprinted methylation in a dose-dependent manner Hum Mol Genet 19 2010 36 51
68. L. Lefebvre, S. Viville, S.C. Barton, F. Ishino, E.B. Keverne, and M.A. Surani Abnormal maternal behaviour and growth retardation associated with loss of the imprinted gene Mest Nat Genet 20 1998 163 169
69. N. Turan, M.F. Ghalwash, S. Katari, C. Coutifaris, Z. Obradovic, and C. Sapienza DNA methylation differences at growth related genes correlate with birth weight: A molecular signature linked to developmental origins of adult disease? BMC Med Genomics 5 2012 10
70. A.N. Imudia, R.H. Goldman, A.O. Awonuga, D.L. Wright, A.K. Styer, and T.L. Toth The impact of supraphysiologic serum estradiol levels on peri-implantation embryo development and early pregnancy outcome following in vitro fertilization cycles J Assist Reprod Genet 31 2014 65 71
71. W.G. Ma, H. Song, S.K. Das, B.C. Paria, and S.K. Dey Estrogen is a critical determinant that specifies the duration of the window of uterine receptivity for implantation Proc Natl Acad U S A 100 2003 2963 2968
72. C. Simon, F. Dominguez, D. Valbuena, and A. Pellicer The role of estrogen in uterine receptivity and blastocyst implantation Trends Endocrinol Metab 14 2003 197 199
73. D. Valbuena, J. Martin, J.L. de Pablo, J. Remohi, A. Pellicer, and C. Simon Increasing levels of estradiol are deleterious to embryonic implantation because they directly affect the embryo Fertil Steril 76 2001 962 968
74. H. Wang, C. Zhou, W. Chen, T. Li, J. Huang, and G. Zhuang Supraphysiological estrogen levels adversely impact proliferation and histone modification in human embryonic stem cells: possible implications for controlled ovarian hyperstimulation assisted pregnancy Eur J Obstet Gynecol Reprod Biol 155 2011 58 64
75. E.D. Albrecht, T.W. Bonagura, D.W. Burleigh, A.C. Enders, G.W. Aberdeen, and G.J. Pepe Suppression of extravillous trophoblast invasion of uterine spiral arteries by estrogen during early baboon pregnancy Placenta 27 2006 483 490
76. T.W. Bonagura, G.J. Pepe, A.C. Enders, and E.D. Albrecht Suppression of extravillous trophoblast vascular endothelial growth factor expression and uterine spiral artery invasion by estrogen during early baboon pregnancy Endocrinology 149 2008 5078 5087
77. G.W. Aberdeen, T.W. Bonagura, C.R. Harman, G.J. Pepe, and E.D. Albrecht Suppression of trophoblast uterine spiral artery remodeling by estrogen during baboon pregnancy: impact on uterine and fetal blood flow dynamics Am J Physiol Heart Circ Physiol 302 2012 H1936 H1944
78. N. Forde, F. Carter, S. di Francesco, J.P. Mehta, M. Garcia-Herreros, and A. Gad et al. Endometrial response of beef heifers on day 7 following insemination to supraphysiological concentrations of progesterone associated with superovulation Physiol Genomics 44 2012 1107 1115
79. P. Devroey, C. Bourgain, N.S. Macklon, and B.C. Fauser Reproductive biology and IVF: ovarian stimulation and endometrial receptivity Trends Endocrinol Metab 15 2004 84 90
80. L.M. Walter, P.A. Rogers, and J.E. Girling The role of progesterone in endometrial angiogenesis in pregnant and ovariectomised mice Reproduction 129 2005 765 777
81. M. Kim, H.J. Park, J.W. Seol, J.Y. Jang, Y.S. Cho, and K.R. Kim et al. VEGF-A regulated by progesterone governs uterine angiogenesis and vascular remodelling during pregnancy EMBO Mol Med 5 2013 1415 1430
82. Z.K. Otrock, J.A. Makarem, and A.I. Shamseddine Vascular endothelial growth factor family of ligands and receptors: review Blood Cells Mol Dis 38 2007 258 268
83. P.H. Andraweera, G.A. Dekker, and C.T. Roberts The vascular endothelial growth factor family in adverse pregnancy outcomes Hum Reprod Update 18 2012 436 457
84. B. Rizk, M. Aboulghar, J. Smitz, and R. Ron-El The role of vascular endothelial growth factor and interleukins in the pathogenesis of severe ovarian hyperstimulation syndrome Hum Reprod Update 3 1997 255 266
85. P. Licht, J. Neuwinger, O. Fischer, E. Siebzehnrubl, and L. Wildt VEGF plasma pattern in ovulation induction: evidence for an episodic secretion and lack of immediate effect of hCG Exp Clin Endocrinol Diabetes 110 2002 130 133
86. B. Luke, M.B. Brown, D.E. Morbeck, S.B. Hudson, C.C. Coddington 3rd, and J.E. Stern Factors associated with ovarian hyperstimulation syndrome (OHSS) and its effect on assisted reproductive technology (ART) treatment and outcome Fertil Steril 94 2010 1399 1404
87. R. Gomez, S.R. Soares, C. Busso, J.A. Garcia-Velasco, C. Simon, and A. Pellicer Physiology and pathology of ovarian hyperstimulation syndrome Semin Reprod Med 28 2010 448 457
88. D. Pietrowski, L. Szabo, M. Sator, A. Just, and C. Egarter Ovarian hyperstimulation syndrome is correlated with a reduction of soluble VEGF receptor protein level and a higher amount of VEGF-A Hum Reprod 27 2012 196 199
89. Z. Wang, L. Xu, and F. He Embryo vitrification affects the methylation of the H19/Igf2 differentially methylated domain and the expression of H19 and Igf2 Fertil Steril 93 2010 2729 2733
90. X.M. Zhao, W.H. Du, H.S. Hao, D. Wang, T. Qin, and Y. Liu et al. Effect of vitrification on promoter methylation and the expression of pluripotency and differentiation genes in mouse blastocysts Mol Reprod Devel 79 2012 445 450
91. A. Pinborg, A.A. Henningsen, A. Loft, S.S. Malchau, J. Forman, and A.N. Andersen Large baby syndrome in singletons born after frozen embryo transfer (FET): is it due to maternal factors or the cryotechnique? Hum Reprod 29 2014 618 627
92. F. Gundogan, D.W. Bianchi, S.A. Scherjon, and D.J. Roberts Placental pathology in egg donor pregnancies Fertil Steril 93 2010 397 404