Assessment of Effect of Some Clinical Factors on Successful Cryopreserved Embryo–Transfer at Yazd Research-Clinical Center of Infertility

Document Type : Original Article


1 Assistant Professor and Fellowship of Infertility, Department of Obstetrics and Gynecology, Yazd Research and Clinical Center of infertility, Shahid Saddoghi University of Medical Sciences, Yazd, Iran.

2 Assistant Professor and Fellowship of Infertility, Department of Obstetrics and Gynecology, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran.


Introduction: Cryopreserved-embryo transfer is one of the most important treatments for infertile couples. While fresh-embryo transfer is mostly approved and concerned, few studies have evaluated the potential effect of clinical factor on the implantation and pregnancy rates in frozen embryo transfer. The aim of this study was to investigate some clinical factors that potentially influence the outcome of cryopreserved-embryo transfer.
Methods: In this retrospective investigation, 372 patients' records that referred to Research and Clinical Center of Infertility and had frozen-embryo transfer cycles were studied from 2009 to 2011. All data of patient`s files fill in the questionnaire form. Data were analyzed by SPSS software version 15 and Kolmogorov-Smirnov, Paired t and t student tests. P value less than 0.05 was considered statistically significant.
Results: Clinical pregnancy-rate in patients under 35 years old was significantly higher than patients aged more than 35 years old (57.7% versus 29.2%). Also, clinical pregnancy-rate in women with FSH more and less than 10 IU/L were 56.3% and 17.5%, respectively (PV=0.0001) which were statistically significant. Other clinical factors such as: the causes of embryo freezing, primary protocols of IVF /ICSI, endometrial thickness and duration of cycle up to day of embryo transfer had no significant effects on frozen-embryo transfer (P>0.05).
Conclusion: Age of women and FSH in third day were the most important factors influencing the clinical pregnancy rate following frozen embryo transfer.


1. Oehninger S, Mayer J, Muasher S. Impact of different clinical variables on pregnancy outcome following
embryo cryopreservation. Mol Cell Endocrinol 2000 Nov 27;169(1-2):73-7.
2. Kassab A, Sabatini L, Tozer A, Zosmer A, Mostafa M, Al-Shawaf T. The correlation between basal serum
follicle-stimulating hormone levels before embryo cryopreservation and the clinical outcome of frozen embryo
transfers. Fertil Steril 2009 Oct;92(4):1269-75.
3. Schalkoff ME, Oskowitz SP, Powers RD. A multifactorial analysis of the pregnancy outcome in a successful
embryo cryopreservation program. Fertil Steril 1993 May;59(5):1070-4.
4. Salumets A, Suikkari AM, Mäkinen S, Karro H, Roos A, Tuuri T. Frozen embryo transfers: implications of
clinical and embryological factors on the pregnancy outcome. Hum Reprod 2006 Sep;21(9):2368-74.
5. Check JH, Choe JK, Nazari A, Fox F, Swenson K. Fresh embryo transfer is more effective than frozen for donor
oocyte recipients but not for donors. Hum Reprod 2001 Jul;16(7):1403-8.
6. Capalbo A, Rienzi L, Buccheri M, Maggiulli R, Sapienza F, Romano S, et al. The worldwide frozen embryo
reservoir: methodologies to achieve optimal results. Ann N Y Acad Sci 2011 May;1221(1):32-9.
7. Ashrafi M, Jahangiri N, Hassani F, Akhoond MR, Madani T. The factors affecting the outcome of frozenthawed
embryo transfer cycle. Taiwan J Obstet Gynecol 2011 Jun;50(2):159-64.
8. El-Toukhy T, Coomarasamy A, Khairy M, Sunkara K, Seed P, Khalaf Y, et al. The relationship between
endometrial thickness and outcome of medicated frozen embryo replacement cycles. Fertil Steril 2008
9. Check JH, Dietterich C, Graziano V, Lurie D, Choe JK. Effect of maximal endometrial thickness on outcome
after frozen embryo transfer. Fertil Steril 2004 May;81(5):1399-400.
10. Orvieto R, Meltzer S, Rabinson J, Zohav E ,Anteby EY, Nahum R. GnRH agonist versus GnRH antagonist in
ovarian stimulation: the role of endometrial receptivity. Fertil Steril 2008 Oct;90(4):1294-6.
11. Eftekhar M, Firouzabadi RD, Karimi H, Rahmani E. Outcome of cryopreserved-thawed embryo transfer in the
GnRH agonist versus antagonist protocol. Iran J Rep Med 2012;10(4):297-302.
12. Eldar-Geva T, Zylber-Haran E, Babayof R, Halevy-Shalem T, Ben-Chetrit A, Tsafrir A, et al. Similar outcome
for cryopreserved embryo transfer following GnRH-antagonist/GnRH-agonist, GnRH-antagonist/HCG or long
protocol ovarian stimulation. Reprod Biomed Online 2007 Feb;14(2):148-54.
13. Eftekhar M, Rahmani E, Eftekhar T. Effect of Adding Human Chorionic Gonadotropin to The Endometrial
Preparation Protocol in Frozen Embryo Transfer Cycles. Int J Fertil Steril. 2012;6(3):175-8.
14. Rimm AA, Katayama AC, Diaz M, Katayama KP. A meta-analysis of controlled studies comparing major
malformation rates in IVF and ICSI infants with naturally conceived children. J Assist Reprod Genet 2004
15. Simon A, Holzer H, Hurwitz A, Revel A, Zentner BS, Lossos F, et al. Comparison of cryopreservation outcome
following intracytoplasmic sperm injection and conventional in vitro fertilization. J Assist Reprod Genet 1998
16. Tucker MJ, Morton PC, Wright G, Ingargiola PE, Jones AE, Sweitzer CL. Factors affecting success with
intracytoplasmic sperm injection. Reprod Fertil Dev 1995;7(2):229-36.