Do blastocysts like fresh air?

WFWW-Do blastocysts like fresh air?

Embryos are very sensitive to their environment. Issues such as temperature, light and atmosphere are critical to proper embryo development and thus to a center’s success rates.

A study in the June 2009 issue of the journal “Fertility and Sterility” supports our decision at Reproductive Partners some time ago to use low oxygen incubators. In this study blastocysts were cultured in atmospheres with either 6% carbon dioxide (CO2) in air, the equivalent to 19% O2, a two-gas system; or 5% O2, 6% CO2, and 90% nitrogen (N2), a three-gas system.

Three hundred ninety six women, were randomized to 197 cultures with the three-gas system and 199 cultures with the two-gas system. The outcome with the three-gas system compared with the two-gas system showed a statistically significantly increased blastocyst rate (47.8% vs. 42.1%), mean number of blastocysts (3.8 vs. 3.3), and number of cryopreserved blastocysts (1.7 vs. 1.1). The mean number of transferred blastocysts was 1.2 versus 1.3. Culture with the three-gas system increased the relative birth rate by 10% compared with the two-gas system (42% vs. 32%, respectively), a statistically significant difference. The overall twin rate was 4.8%.
They concluded that blastocyst culture with low-oxygen (5%) versus high-oxygen (19%) concentration yielded a better blastocyst outcome and a marked improvement in birth rate.