Objective: To evaluate whether blastocyst culture and transfer in patients with low oocyte number can effectively improve the outcome of in vitro fertilization-embryo transfer treatment.
Methods: Retrospectively analyze 59 couples received conventional in vitro fertilization and embryo transfer (IVF-ET) treatment in our center from January to February 2000. Twenty-one couples had blastocyst culture and day 5 embryo transfer and another 38 couples had day 2 embryo transfer as the control. Their clinical and laboratory results were compared between these two groups.
Results: In day 5 group the mean oocytes retrieved were (6.6 +/- 2.8), the clinical pregnancy rates (PRs) was 43% and the life delivery rate was 38%; while in day 2 group the results were (6.9 +/- 3.7), 37% and 29% respectively. There was no significant difference between two groups. No high-order multiple birth occurred in day 5 group, but in day 2 group there were two cases: one with triplets and another with pentadriplet who had the embryos reduction.
Conclusions: These results demonstrate that nonselective blastocyst culture and transfer in patients with low oocyte number seems not effectively to improve the PRs and the delivery rate, but may decrease the occurrence of multiple birth without affecting the final pregnancy results when compared with conventional day 2 transfer.