Early cleavage is a valuable addition to existing embryo selection parameters: a study using single embryo transfers

Abstract

BACKGROUND: To reduce the twin pregnancy rate, elective single embryo transfer (eSET) is increasingly implemented. Improvement of the results obtained with eSET can be achieved by better selection of the most viable embryo. This study investigated the predictive value of early cleavage (EC) as an additional parameter for selecting the embryo with the highest implantation potential by using data from SET's. METHODS: Data from 165 SET's were retrospectively evaluated. Cleavage to the 2-cell stage was determined 23 -26 h after injection or 25 -28 h after insemination. Selection of the embryo to be transferred was based on cell morphology and cell number on the day of transfer, not on the EC status. Additional information on the predictive value of EC on developmental potential was obtained by analysing 253 transfers with two embryos (double embryo transfer, DET) and blastocyst formation of 1160 surplus embryos. Logistic regression was used to determine the predictors of pregnancy or blastocyst development. RESULTS: A significantly higher pregnancy rate was observed after transfer of single EC embryos compared to single non-EC embryos (46 versus 18%). This result was confirmed by the significantly higher pregnancy rate after DET with two EC embryos as compared to DET with two non-EC embryos (45 versus 25%) and the blastocyst formation of EC embryos compared to non-EC embryos (66 versus 40%). Logistic regression showed that EC is an independent predictor for both pregnancy and blastocyst development in addition to cell morphology and cell number. CONCLUSIONS: In order to improve the selection of the embryo with the highest implantation potential, selection for transfer should not be based on cell number and morphology on the day of transfer alone, but also on early cleavage status.

Evaluation of the safety of time-lapse observations for human embryos

“…Among of these criteria, morphologic features have been used extensively in selecting good-quality embryos. However, selection for transfer should not be based on cell number and morphology solely on the day of transfer [8].…”

Relationship between meiotic spindle characteristics in human oocytes and the timing of the first zygotic cleavage after intracytoplasmic sperm injection

“…Previous studies have observed that human embryos that cleaved earlier to the 2-cell stage exhibited a higher rate of blastocyst formation [15,16] compared with late cleaving embryos, and that transfer of the early cleaving embryos led to significantly higher implantation and pregnancy rates Fig. 3 Comparison of pregnancy rates between the early and late cleaved human embryos.…”

Observation of human embryonic behavior in vitro by high‐resolution time‐lapse cinematography

“…However, this quality control approach needs improvement with implantation rates of good quality embryos limited to 30-40 % per embryo transfer (ET) [7]. Indeed, based on the standard morphological assessment, ET with early cleavage-stage embryos has a better chance of achieving pregnancy than ET with blastocysts [8,9]. On the other hand, embryos at the blastocyst stage are less likely to be aneuploid, and reported implantation rates are higher when blastocysts have been transferred [10].…”