Purpose
To evaluate the effect of the size of zona pellucida opening by laser assisted hatching for frozen cleaved embryo that were
thawed after both fresh and frozen cleaved embryo transfer cycles failed and were cultured to blastocyst after thawing in
patients with multiple implantation failures.
Materials and methods
Of 101 consecutive procedures (October 2003 to June 2006), 30 patients declined to perform assisted hatching and were selected
as control group, 40 patients had 40 μm opening of the zona (October 2003 to January 2005), 31 patients had 50% of the zona
opening (February 2005 to June 2006).
Results
The pregnancy, implantation and delivery rates were significantly higher in 50% opening group (74%, 52% and 65%) compared
to control group (17%, 10% and 13%; P < 0.01) and 40 μm opening group (43%, 27% and 38%; P < 0.04).
Conclusions
The size of the zona pellucida opening may affect the outcome of frozen cleaved embryo transfer.
Keywords Assisted hatching - Blastocyst - Frozen embryo - Laser - Multiple implantation failures
Capsule
The size of the zona pellucida opening by laser assisted hatching may affect the outcome of frozen cleaved embryo transfer
in multiple implantation failures.