The influence of the type of embryo culture media on the outcome of IVF/ICSI cycles

Objective Embryo culture media are important factors in IVF, which can significantly influence clinical outcome of IVF/ICSI cycles. Despite this, it is still not completely clear which formulation is most optimal and whether sequential or continuous media should be favored. Materials and methods This study retrospectively analyzed the outcome of IVF/ICSI cycles with regard to different types of culture media used to culture embryos, namely sequential and two types of single step continuous embryo culture media. Results If the data were combined for both types of single step continuous embryo culture media the only significant difference we observed was the proportion of poor quality embryos on day 3, which was significantly higher (16.9% vs. 22.5%; P = 0.017) in the sequential media. The pregnancy (55.1% vs. 40.5%; P = 0.113) and live birth rates (42.9% vs. 33.8%; P = 0.308) were lower in continuous media, although the difference was not statistically significant. Furthermore, the blastocyst rate (sequential vs. continuous; 47.4% vs. 47.3%; P = 1), and birthweight (3280 ± 630g vs. 3272 ± 575g; P = 0.96) did not significantly differ regardless of the medium used to culture embryos. Additional comparison of each type of continuous medium to sequential media revealed that the difference in the quality of cleavage stage embryos for combined data of both continuous culture media may be derived from the group of cycles were SAGE 1-Step was used to culture embryos. Conclusion These results therefore indicate that continuous media can be equivalent to sequential media and could help lower the workload in busy IVF labs without impairing the clinical results. Although, caution is needed because this study is limited by its retrospective design. To confirm the results, especially in terms of live birth rates and perinatal outcome, a prospective study is needed with a higher number of included couples.