Micromanipulation of cryopreserved embryos and cryopreservation of micromanipulated embryos in PGD

Reliable preimplantation genetic diagnosis in thawed human embryos vitrified at cleavage stages without biopsy

“…Ciotti et al [15] reported that biopsy and FISH in thawed embryos was possible but technical improvements were needed. Baart et al [18] were able to perform FISH on blastomeres removed from frozen-thawed embryos although no pregnancy was reported in that study.…”

“…The slides were air-dried, washed in PBS, and dehydrated in serial dilutions of ethanol for 2 min each. Commercially available multicolor FISH probes for chromosomes 13,15,16,18,21,22, X, and Y (Vysis, Downers Grove, IL, USA) were applied on nuclei of biopsied blastomeres in two consecutive rounds. Codenaturation, hybridization, washing, and nuclear staining steps were carried out in each round.…”

“…However, several reports suggest that post-thaw survival rates of embryos biopsied on day 3 are significantly lower than those not subjected to embryo biopsy before freezing [7,9,[13][14][15]. The exact cause of this phenomenon has not been thoroughly investigated but increased susceptibility to cryodamage due to the hole in the zona pellucida created for biopsy may be a plausible explanation [10].…”

“…To the best of our knowledge, only three small studies evaluating PGD on thawed embryos frozen at cleavage stages have been published [15,17,18]. Successful pregnancies have been reported in one of those studies [17].…”

A live birth after transfer of a day 2 embryo derived from frozen-thawed zygotes that had undergone polar body biopsy: a case report

“…It has been clearly demonstrated that the biopsy of thawed embryos and of embryos derived from thawed oocytes is feasible and that the FISH analysis is possible on both surviving and lysed cells (12). However, the results of the FISH analysis are then lately obtained, and ET should be postponed to a later developmental stage.…”