Developmental potential of fully intact and partially damaged cryopreserved embryos after laser-assisted removal of necrotic blastomeres and post-thaw culture selection.
OBJECTIVE
Partially damaged frozen and thawed embryos are currently considered to have a lower viability than intact ones. This study was undertaken to compare the performance of intact frozen and thawed embryos with that of partially damaged embryos after removal of the necrotic blastomeres.


METHODS
Observational clinical series.


METHODS
Private hospital.


METHODS
Three hundred twenty-six infertile couples undergoing frozen embryo transfer.


METHODS
Removal of necrotic blastomeres from frozen-thawed human embryos.


METHODS
Pregnancy and implantations rates.


RESULTS
Outcomes of frozen embryo transfer cycles in which all embryos were fully intact (group 1) were compared with those in which all embryos have lost 1-2 blastomeres (group 2) or 3-4 blastomeres (group 3). Laser-assisted hatching was performed in all embryos, and necrotic blastomeres were removed from partially damaged embryos on this occasion. Only embryos that resumed mitotic activity after thawing were transferred. Comparable clinical pregnancy rates (PR) (38.7%, 39.6%, and 29.4%), delivery rates (34.4%, 34.0%, and 29.4%), and implantation rates (21.6%, 21.4%, and 17.2%) were obtained in groups 1, 2, and 3, respectively.


CONCLUSIONS
The developmental potential of partially damaged frozen and thawed embryos can be equivalent to fully survived embryos if the necrotic blastomeres are removed from the partially damaged embryos and only those of them that show post-thaw cleavage are selected for transfer.
Rienzi
Laura
L
Centre for Reproductive Medicine, European Hospital, Rome, Italy. rienzi.@icsiroma.it
Ubaldi
Filippo
F
Iacobelli
Marcello
M
Minasi
Maria Giulia
MG
Romano
Stefania
S
Ferrero
Susanna
S
Sapienza
Fabio
F
Baroni
Elena
E
Tesarik
Jan
J
Greco
Ermanno
E
D000328:Adult; D001757:Blastomeres / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D002478:Cells, Cultured; D016009:Chi-Square Distribution; D015925:Cryopreservation / Q000379:methods*; D046149:Embryo Culture Techniques / Q000379:methods*; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D005260:Female; D006801:Humans; D007834:Lasers; D009336:Necrosis / Q000196:embryology / Q000473:pathology; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies