Time-lapse evaluation of human embryo development in single versus sequential culture media--a sibling oocyte study

Abstract

Objective: To compare the dynamics of early development between embryos cultured in single and sequential media.

Design: Randomized, comparative study.

Setting: Private IVF centre.

Patients: A total of 446 metaphase II oocytes from 51 couples who underwent oocyte retrieval procedure for intracytoplasmic sperm injection. Forty-nine resulted in embryo transfer.

Intervention: Oocytes were split between single and sequential media produced by the same manufacturer and cultured in a time-lapse incubator.

Main outcome measures: Morphokinetic parameters until the embryos reached the 5-cell stage (t5), utilization, clinical pregnancy and implantation rates.

Results: Embryos cultured in single media were advanced from the first mitosis cycle and reached 2- to 5-cell stages earlier. There was not any difference between the durations for cell cycle two (cc2 = t3-t2) and s2 (t4-t3). The utilization, clinical pregnancy and implantation rates did not differ between groups. The proportion of cryopreserved day 6 embryos to two pronuclei oocytes was significantly higher in sequential than in single media.

Conclusions: Morphokinetics of embryo development vary between single and sequential culture media at least until the 5-cell stage. The overall clinical and embryological parameters remain similar regardless of the culture system.

Figures

Fig. 1

Cleavage-stage scoring; Traffic lights; green is ‘good for transfer’, yellow is ‘transferable’, and presence of one red is ‘not good for transfer’

Fig. 2

Time-lapse monitoring of two embryos from one patient of which both implanted (from top-left to bottom-right). Please note that the embryo on the left appears to be advanced from the first mitosis cycle and has less fragmentation as compared to the one on the right. However, compaction occurs earlier on the embryo to the right, eventually both forming blastocysts at day 5