The effect of two distinct levels of oxygen concentration on embryo development in a sibling oocyte study

Esti Kasterstein, Deborah Strassburger, Daphna Komarovsky, Orna Bern, Alisa Komsky, Arieh Raziel, Shevach Friedler, Raphael Ron-El

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Purpose: This prospective randomized study used sibling oocytes of 258 women with ≥8 oocytes to compare the effect of 5 % O2 versus 20 % O2 concentrations on embryo development and clinical outcome. Methods: Oocytes of each case were divided between incubators with either 5 % or 20 % O2 concentration. Outcome measures were fertilization, cleavage, embryo quality, blastocyst formation, and implantation, pregnancy and live birth rates. Results: Fertilization and cleavage rates were similar in both groups. The 5 % O2 group had significantly more blastomeres (P < 0.05) and more top-quality embryos on day 3 (P < 0.02), as well as significantly more available embryos for transfer (31.6 % vs. 23.1 % for the 20 % O2 group; P < 0.0001). There were significantly more cycles with good embryos in the 5 % group (76/258) than in the 20 % group (38/258) (P < 0.0001). Implantation and pregnancy rates were significantly higher for 5 % O2 embryos (P < 0.03 and P < 0.05, respectively). Live birth rates per embryo transfer were 34.2 % and 15.8 %, respectively, P < 0.05. Conclusions: Implantation, pregnancy and live birth rates are higher, and more good quality embryos are available for transfer and freezing with reduced rather than with atmospheric oxygen concentrations during embryo incubation.

Original languageEnglish
Pages (from-to)1073-1079
Number of pages7
JournalJournal of Assisted Reproduction and Genetics
Issue number8
StatePublished - 1 Aug 2013
Externally publishedYes


  • Blastocysts
  • Embryo culture
  • Oxygen
  • Pregnancy rates
  • Preimplantation development

ASJC Scopus subject areas

  • Reproductive Medicine
  • Genetics
  • Obstetrics and Gynecology
  • Developmental Biology
  • Genetics(clinical)


Dive into the research topics of 'The effect of two distinct levels of oxygen concentration on embryo development in a sibling oocyte study'. Together they form a unique fingerprint.

Cite this