Abstract
Purpose: To report on successful birth after the transfer of postthawed human zygotes that were vitrified using a conventional straw for the purpose of protecting them from infections and a low-toxicity cryoprotectant that is commercially sold.
Methods: A primary infertile couple presented at our IVF program. After being checked for fertilization, the embryos were not transferred to the uterus at that cycle. Instead, all of them were cryopreserved at the 2-pronuclei stage using our original vitrification method. After the vitrification and warming of four zygotes, two embryos were transferred into the uterus.
Results: Twenty-one 2-pronuclei embryos were vitrified in liquid nitrogen. After 2 embryos were thawed and transferred, successful pregnancy was the outcome, and a healthy boy was born at term.
Conclusions: Vitrification is a simple procedure and requires less time than slow freezing. Vitrification of zygotes in a conventional straw seems to be sufficient for viability and works to store the zygotes safely.
KEY WORDS: IVF, straw, safety, vitrification, zygote
Full Text
The Full Text of this article is available as a PDF (147.2 KB).
REFERENCES
- 1.Whittingham DG, Leibo SP, Mazur P. Survival of mouse embryos frozen to −196^C and −269^C. Science. 1972;178:411–414. [PubMed] [Google Scholar]
- 2.Trounson A, Mohr L. Human pregnancy following cryopreservation; thawing and transfer of an eight-cell embryo. Nature. 1983;305:707–709. doi: 10.1038/305707a0. [DOI] [PubMed] [Google Scholar]
- 3.Rall WF, Fahy GM. Ice-free cryopreservation of mouse embryos at −196^C by vitrification. Nature. 1985;313:573–575. doi: 10.1038/313573a0. [DOI] [PubMed] [Google Scholar]
- 4.Gordts S, Roziers P, Campo R, Noto V. Survival and pregnancy outcome after ultrarapid freezing of human embryos. Fert Sterl. 1990;53:469–72. [PubMed] [Google Scholar]
- 5.Kruger TF, Menkveld R, Stander FS, Lombard CJ, Van der, Merwe JP, Van Zyl JA. Sperm morphologic features as a prognostic factor in in vitro fertilization. Fert Ster. 1986;46:1118–1123. doi: 10.1016/s0015-0282(16)49891-2. [DOI] [PubMed] [Google Scholar]
- 6.Kumon M, Kumasako Y, Utsunomiya T, Araki Y. A vitrification method by means of a straw to prevent infections in mouse pronuclear embryos. J Mamm Ova Res. 2003;20:124–128. [Google Scholar]
- 7.Yokota Y, Sato S, Yokota M, Ishikawa Y, Makita M, Asada T, Araki Y. Successful pregnancy following blastocyst vitrification. Fertil Steril. 2000;15:1802–1803. doi: 10.1093/humrep/15.8.1802. [DOI] [PubMed] [Google Scholar]
- 8.Lane M, Schoolcraft WB, Gardner DK. Vitrification of mouse and human blastocysts using a novel cyroloop container-less technique. Fert Ster. 1999;72:1073–1078. doi: 10.1016/s0015-0282(99)00418-5. [DOI] [PubMed] [Google Scholar]
- 9.Vajta G, Lewis IM, Kuwayama M, Greve T, Callesen H. Sterile application of the open pulled straw (OPS) vitrification method. Cryo Lett. 1998;19:389–392. [Google Scholar]
- 10.Choo BS, Shaw J, Kuleshova L, Trounson AO. A comparison of rapid and slow cooling protocols on the survival of bovine primordial follicles cyropreserved within ovarian tissue pieces. Cryobiology. 2000;39:284. [Google Scholar]
- 11.Matino A, Songsasen N, Leibo SP. Development into blastocysts of bovine oocytes cryopreserved by ultra-rapid cooling. Biol Reprod. 1996;54:1059–1069. doi: 10.1095/biolreprod54.5.1059. [DOI] [PubMed] [Google Scholar]
- 12.Bielanski A, Nadin-Davis S, Sapp T, Lutze-Wallace Viral contamination of embryos cryopreserved in liquid nitrogen. Cryobiology. 2000;40:110–116. doi: 10.1006/cryo.1999.2227. [DOI] [PubMed] [Google Scholar]
- 13.Fountain D, Ralston M, Higgins N, Gorlin JB, Uhl L, Wheeler C, Antin JH, Churchill WH, Benjamin RJ. Liquid nitrogen freezers: A potential source of microbial contamination of hematopoietic stem cell components. Transfusion. 1997;37:585–591. doi: 10.1046/j.1537-2995.1997.37697335152.x. [DOI] [PubMed] [Google Scholar]
- 14.Ohta N, Nohara M, Kojimahara T, Ito M, Saito T, Nakahara K, Tezuka N, Saito H, Hiroi M. Ultrarapid freezing of human embryos by vitrification method: A case of delivery. Jpn. J Fertil Steril. 1996;41:276–279. [Google Scholar]
- 15.Jelinkova L, Selman HA, Arav A, Strehler E, Reeka N, Sterzik K. Twin pregnancy after vitrification of 2-pronuclei human embryos. Fert Ster. 2002;77:412–414. doi: 10.1016/s0015-0282(01)02992-2. [DOI] [PubMed] [Google Scholar]
- 16.Mukaida T, Wada S, Takahashi K, Pedro PB, An TZ, Kasai M. Vitrification of human embryos based on the assessment of suitable conditions for 8-cell mouse embryos. Hum Reprod. 1998;13:2874–2879. doi: 10.1093/humrep/13.10.2874. [DOI] [PubMed] [Google Scholar]
- 17.Scheffen B, Van Der, Zwalmen P, Massip A. A simple and efficient procedure for preservation of mouse embryos by vitrification. Cryo Lett. 1986;7:260–269. [Google Scholar]