Abstract
Purpose
The aim was to investigate if improved survival rates could be achieved using a new formulation of solutions for slow freezing of human cleavage stage embryos.
Methods
The evaluation was divided into two parts. The first part was a retrospective analysis of results obtained after freezing and thawing of day 3 embryos from 400 women using an old formulation of cryopreservation solutions compared to results from 108 women for which cryopreservation had been performed using new compositions of solutions. The second part was prospective, adding cycles until similar numbers of patients had been included in both groups. In total, 2274 embryos from 897 patients were thawed using the old formulation of solutions while 1273 embryos from 542 patients were frozen and thawed using the new solutions. The primary endpoint was survival rate.
Results
With the new solutions, the survival rate increased from 82.1 to 94.4 % and the complete embryo survival rate increased from 54.9 to 81.3 %. The implantation rate, clinical pregnancy rate per embryo transfer, and per cycle were 28.2, 45.2, and 43.7 %, respectively, using the old formulations of cryosolutions. With the new solutions, the results reached 33.7, 54.1, and 54.1 %, respectively. All differences in results were statistically significant. The number of cancelled embryo transfers due to no survived embryos was 18 with the old solutions and 0 using the new solutions.
Conclusion
With the new composition of solutions for slow freezing and thawing of embryos, significantly improved results were obtained. Additionally, the number of cancelled embryo transfers was reduced.
Similar content being viewed by others
References
Lassalle B, Testart J, Renard JP. Human embryo features that influence the success of cryopreservation with the use of 1,2propanediol. Fertil Steril. 1985;44(5):645–51.
Kupka MS, D’Hooghe T, Ferraretti AP, de Mouzon J, Erb K, Castilla JA, et al. Assisted reproductive technology in Europe, 2011: results generated from European registers by ESHRE. Hum Reprod. 2016;31(2):233–48. doi: 10.1093/humrep/dev319.
Debrock S, Peeraer K, Fernandez Gallardo E, De Neubourg D, Spiessens C, D’Hooghe TM. Vitrification of cleavage stage day 3 embryos results in higher live birth rates than conventional slow freezing: a RCT. Hum Reprod. 2015;doi: 10.1093/humrep/dev134.
Pouget O, Scalici E, Hoa-Ferrieres A, Deutsch-Bringer S, Gala A, Dechaud H, Hamamah S. Comparison of frozen embryo transfer outcomes at blastocyst stage according to freezing method and type of endometrial preparation. GynecolObstetFertil. 2015;doi: 10.1016/j.gyobfe.2015.01.012.
Zeilmaker GH, Alberda AT, van Gent I, Rijkmans CM, Drogendijk AC. Two pregnancies following transfer of intact frozen-thawed embryos. FertilSteril. 1984;42(2):293–6.
Chen C. Pregnancy after human oocyte cryopreservation. Lancet. 1986;1(8486):884–6.
Fabbri R, Porcu E, Marsella T, Rocchetta G, Venturoli S, Flamigni C. Humanoocyte cryopreservation: new perspectives regarding oocyte survival. Hum Reprod. 2001;16(3):411–6.
Cohen J, Simons RF, Fehilly CB, Fishel SB, Edwards RG, Hewitt J, et al. Birth after replacement of hatching blastocyst cryopreserved at expanded blastocyst stage. Lancet. 1985;1(8429):647.
Testart J, Lassalle B, Belaisch-Allart J, Hazout A, Forman R, Rainhorn JD, et al. High pregnancy rate after early human embryo freezing. FertilSteril. 1986;46(2):268–72.
Edgar DH, Karani J, Gook DA. Increasing dehydration of human cleavage-stage embryos prior to slow cooling significantly increases cryosurvival. Reprod Biomed Online. 2009;19(4):521–5.
Gardner DK, Maybach J, Lane M. Hyaluronan and RHSA increase blastocyst cryosurvival. Proc 17th World Congress on Fertility and Sterility, Melbourne; 2001. p. 226
Lane M, Maybach JM, Hooper K, Hasler JF, Gardner DK. Cryo-survival and development of bovine blastocysts are enhanced by culture with recombinant albumin and hyaluronan. MolReprod Dev. 2003;64:70–8.
Seki S, Mazur P. The dominance of warming rate over cooling rate in the survival of mouse oocytes subjected to a vitrification procedure.Cryobiology. 2009;doi: 10.1016/j.cryobiol.2009.04.012.
Mazur P, Seki S. Survival of mouse oocytes after being cooled in a vitrification solution to −196°C at 95° to 70,000°C/min and warmed at 610° to 118,000°C/min: a new paradigm for cryopreservation by vitrification.Cryobiology. 2011;doi: 10.1016/j.cryobiol.2010.10.159.
O’Shea LC, Hughes C, Kirkham C, Mocanu EV, O’Shea LC, Hughes C, et al. The impact of blastomere survival rates on developmental competence of cryo-thawed day 2 embryos. Eur J ObstetGynecolReprod Biol. 2016;197:98–102. doi:10.1016/j.ejogrb.2015.11.040.
Van Landuyt L, Van de Velde H, De Vos A, Haentjens P, Blockeel C, Tournaye H, et al. Influence of cell loss after vitrification or slow-freezing on further in vitro development and implantation of human day 3 embryos. Hum Reprod. 2013;28(11):2943–9. doi:10.1093/humrep/det356.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Funding
This study was funded by China Natural Science Fundation (Grant No.81370761) and China National Key Technology Support Program (Grant No. N20120266-04).
Additional information
Capsule
With the new composition of solutions for slow freezing and thawing of embryos, significantly improved results were obtained. Additionally, the number of cancelled embryo transfers was reduced.
Rights and permissions
About this article
Cite this article
Fang, L., Jin, L., Li, E. et al. Clinical evaluation of two formulations of slow-freezing solutions for cleavage stage embryos. J Assist Reprod Genet 33, 1389–1393 (2016). https://doi.org/10.1007/s10815-016-0778-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10815-016-0778-1