Laser-assisted hatching of cryopreserved-thawed embryos by thinning one quarter of the zona.
Laser-assisted hatching is little documented in the literature regarding its efficacy in cryopreserved-thawed (CT) embryo transfer cycles. The aim of the present study was to evaluate in a randomized manner the efficacy of thinning one quarter of the zona pellucida of CT embryos to a depth of 50-80% of the original thickness, via laser treatment (the qLZT-AH procedure), in improving implantation and pregnancy rates. Two populations were studied: population I, patients who had all their supernumerary embryos cryopreserved, regardless of their morphology, and population II, patients at risk of ovarian hyperstimulation syndrome who had all their embryos cryopreserved. Artificial and natural protocols were used for the embryo transfers. A total of 350 laser-thinned CT embryos were compared with 352 intact zona embryos. No difference in implantation or pregnancy rate was found after using qLZT-AH in either population. These findings suggest that qLZT-AH should not be routinely performed in cryopreserved embryo programmes.
Petersen
Claudia Guilhermino
CG
Centre for Human Reproduction Prof Franco Junior, Av. Prof. João Fiusa 689-CEP 14025-310, Ribeirão Preto, SP-Brazil. petersenclaudia@crh.com.br
Mauri
Ana Lucia
AL
Baruffi
Ricardo Luiz Razera
RL
Oliveira
João Batista Alcântara
JB
Felipe
Valeria
V
Massaro
Fabiana Cagnoto
FC
Franco
Jose Gonçalves
JG
D000328:Adult; D015925:Cryopreservation / Q000379:methods; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D053685:Laser Therapy; D011247:Pregnancy; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods; D015044:Zona Pellucida / Q000648:ultrastructure*