Comparison of 2, 5, and 20 % O2 on the development of post-thaw human embryos.

PURPOSE: The objective of this study is to investigate the effect of 2, 5, and 20 % O2 on post-thaw day 3 human embryo culture until blastocyst stage. METHODS: One hundred fifty-five day 3 human embryos were used. One hundred twenty out of 155 embryos were recovered after thawing. Surviving embryos were distributed into 2, 5, or 20 % O2 groups and cultured for 2.5 days. At the end of culture, blastocyst formation was assessed, and then, embryos were collected for RT-qPCR or immunofluorescence analysis. RESULTS: Using visible blastocoel to define blastocyst formation, 58.7 % (27/46) of surviving day 3 embryos formed blastocyst at 2 % O2, 63.6 % (28/44) at 5 % O2, and 66.7 % (20/30) at 20 % O2. The difference in blastocyst formation rates was not significant. Average blastocyst cell number was 119.44 ± 11.64 at 2 % O2, 142.55 ± 22.47 at 5 % O2, and 97.29 ± 14.87 at 20 % O2. Average apoptotic rate was 4.7 % ± 0.4 % for blastocyst formed at 2 % O2, 3.5 % ± 0.7 % at 5 % O2, and 5.8 % ± 1.1 % at 20 % O2. Apoptosis rate was significantly lower for blastocysts formed at 5 % O2 (p < 0.05). Compared with gene expression levels at 5 % O2, which were arbitrarily set as "1," 20 % O2 is associated with significantly higher expression of BAX (2.14 ± 0.47), G6PD (2.92 ± 1.06), MnSOD (2.87 ± 0.88), and HSP70.1 (8.68 ± 4.19). For all genes tested, no significant differences were found between 2 and 5 % O2. CONCLUSION: The result suggests that development of cryopreserved human embryos from day 3 to blastocyst stage benefits from culture at 5 % O2.

Better IVF outcomes following improvements in laboratory air quality.

BACKGROUND: It has been proved that air quality is crucial for the success of IVF because of the presence of volatile organic compounds (VOCs), microbes, and perfumes, all of which can be harmful to embryo development in vitro. Therefore IVF laboratories are equipped with high efficiency particulate air (HEPA), and activated carbon filters plus positive pressure for air particulate control, with or without CODA system. Here we introduce a new technology using specially treated Honeycomb matrix media aligned in the Landson ™ series system for our laboratory air purification and its impact on IVF outcome. METHODS: Air samples were collected outside and inside the laboratory, and intra-incubator at three different time points, before and after changing carbon filters and after Landson system installation, and we correlated air compounds measure variation with IVF outcome from 1403 cycles. RESULTS: An improvement of air quality was confirmed with passages of total VOCs from 0.42 mg/m(3), 30.48 mg/m(3), 9.62 mg/m3, to 0.1 mg/m(3), 2.5 mg/m(3), 2.19 mg/m(3) through 0.07 mg/m(3), 0.16 mg/m(3), 0.29 mg/m(3), outside the laboratory, inside laboratory and intra-incubator respectively at three separated air sampling times. A clear decrease was observed in some VOCs such as formaldehyde, ethylene, acethylene, propylene, SO2, pentane, NOx, benzene, Hallon-1211, CFC and alcohol. At the same time a significant difference (P<0.05) was found between the third testing time TT3 after carbon filter change and Landson system installation and the first testing time TT1 before carbon filter change in fertilization rate 83.7 % vs 70.1 %, embryo cleavage rate 97.35 % vs 90.8 %, day 5 blastocyst formation rate 51.1 % vs 41.7 %, and pregnancy/implantation rates 54.6 %, 34.4 % vs 40.6 %, 26.4 %. CONCLUSION: Air purification by the new technology of Landson ™ series significantly improved IVF laboratory air quality, and embryo quality, thus increased pregnancy and implantation rates.