Relevance of assisted hatching in an oocyte donation programme using egg cryobanking: a prospective randomised study.
OBJECTIVE
The objective of this prospective randomised study was to evaluate if there is an improvement in clinical outcomes when assisted hatching (AH) is performed in embryos derived from vitrified/warmed oocytes in an ovum donation programme using egg cryobanking.


METHODS
Sixty oocyte recipients in a donation programme using egg cryobanking were randomly allocated to the assisted hatched (AH, n=30) or control group (n=30). The pregnancy and implantation rates were compared between the groups.


RESULTS
A total of 288 vitrified oocytes were warmed for the 60 recipients. Of the 288 vitrified oocytes, 94.8% survived. All surviving oocytes were sperm injected, and 83.5% underwent fertilisation. There were 172 good-quality embryos selected for transfer. The total pregnancy rate was 40%. The pregnancy rate did not differ between the AH and control groups (43.3% and 33.3%, respectively, p=0.1967), but AH resulted in a higher implantation rate (31.6% vs. 18.4%, p=0.0206).


CONCLUSIONS
Our study demonstrates the effectiveness of AH in embryos derived from warmed oocytes. Our results also suggest that oocyte cryopreservation can be considered as a tool for providing highly successful outcomes in an egg donor programme.
Fertility - Assisted Fertilization Centre, Av. Brigadeiro Luis, 4545. São Paulo, SP 01401 002, Brazil.
Rita de Cássia S
Rde C
Figueira
Daniela Paes de Almeida Ferreira
DP
Braga
Amanda S
AS
Setti
Assumpto
A
Iaconelli
Edson
E
Borges
D000328:Adult; D015925:Cryopreservation / Q000379:methods*; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D018587:Oocyte Donation / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D058989:Vitrification; D015044:Zona Pellucida / Q000502:physiology