Objective: To compare two blastocyst culture systems: culture on Vero cells and sequential media in the same time period.
Design: Retrospective study.
Setting: Institutional practice assisted reproductive technology center.
Patient(s): Ninety-nine selected patients undergoing IVF with blastocyst culture.
Intervention(s): In vitro fertilization and transfer of at least one expanded blastocyst after culture using either Vero cells or sequential media (S(2) medium).
Main outcome measure(s): Blastocyst, pregnancy, and implantation rates.
Result(s): The blastocyst formation rate (41.6% vs. 31.6%) is significantly increased with sequential media compared with the coculture system, but there is no statistically significant difference in the pregnancy and implantation rates (39.5% vs. 38.6% and 23.7% vs. 15.1%, respectively).
Conclusion(s): Blastocyst culture on sequential media offers a better dynamic of embryo development (22% vs. 13.6% blastocyst at day 5). There was no statistically significant difference between the two groups in the take-home baby rate (18 vs. 12).