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

Abstract

Purpose This prospective randomized study used sibling oocytes of 258 women with ≥8 oocytes to compare the effect of 5 % O 2 versus 20 % O 2 concentrations on embryo development and clinical outcome. Methods Oocytes of each case were divided between incubators with either 5 % or 20 % O 2 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 % O 2 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 % O 2 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 % O 2 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.

Oxidative Stress Delays Prometaphase/Metaphase of the First Cleavage in Mouse Zygotes via the MAD2L1‐Mediated Spindle Assembly Checkpoint

“…Our results showed that H 2 O 2 treatment did not significantly reduce the rates of 2-cell formation, 4-cell formation, or 8-cell formation ( P > 0.05) but produced a significant decrease in the rates of blastocyst formation ( P < 0.05) (Figure 1), which was similar to phenomena observed in the clinic [29, 30]. Therefore, we considered that treatment with 0.03 mM H 2 O 2 reflected clinical relevance and was suitable for inducing oxidative damage in the treated group.…”

Can we use incubators with atmospheric oxygen tension in the first phase of in vitro fertilization? A retrospective analysis

“…Pregnancies ending with a live birth were 70 % (n=21/30) in IVF group and 85 % (n=29/34) in ICSI group, respectively (p=0.23). [4,18,19]; others reported an improvement in clinical outcomes even though embryo quality was not affected [3,9,[20][21][22]; lastly, some authors observed an improvements in embryo quality without an increase in overall pregnancy results [23][24][25][26].…”

Can we use incubators with atmospheric oxygen tension in the first phase of in vitro fertilization? A retrospective analysis

“…Results obtained are largely inconsistent. Some papers highlighted benefits in both embryo quality and clinical outcome [4,18,19]; others reported an improvement in clinical outcomes even though embryo quality was not affected [3,9,[20][21][22]; lastly, some authors observed an improvements in embryo quality without an increase in overall pregnancy results [23][24][25][26].…”