Effect of embryo biopsy on the clinical results of chromosomally normal cryopreserved embryos: research by the Instituto Bernabeu.

The techniques for chromosomal analysis of embryos that we currently apply at the Instituto Bernabeu offer a diagnosis in less than 24 hours. This allows us to perform biopsies on blastocysts on day 5 of culture and conclude the fresh transfer of the chromosomally normal embryos on day 6 of culture. Sometimes it is necessary to delay transfer to a later cycle, which makes it necessary to cryopreserve the biopsied embryos, which may, in theory, be more sensitive to cryopreservation.Therefore, we considered whether the biopsy process may affect the embryo’s capacity to survive cryopreservation.

We have performed a study in which we analysed a total of 441 cycles with transfer of biopsied embryos. These were divided into two groups: embryos used for fresh transfer and those that were cryopreserved and subsequently transferred. The clinical results of these cycles were studied (positive pregnancy rate, biochemical miscarriage and clinical pregnancy), and no statistically significant differences were found between both groups. This enables us to guarantee to our patients the same probabilities of pregnancy with biopsied embryos, both in fresh transfer and in transfer after thawing.

The conclusions of this research, which is highly relevant to the new possibilities offered by embryo biopsy, have been accepted as an oral presentation by the scientific committee of the forthcoming congress of the Spanish Fertility Society, SEF Congress – the most important meeting in Spain of specialists in reproductive medicine – which will take place in Malaga from 19 to 21 May.

EFFECT OF EMBRYO BIOPSY ON THE CLINICAL RESULTS OF CHROMOSOMALLY NORMAL CRYOPRESERVED EMBRYOS.Mª.C. Tió, A. Rodriguez, J. Ten, J. Guerrero, B. Moliner, J. Ll. Aparicio, R. Bernabeu.