Effect of the size of zona pellucida opening by laser assisted hatching on clinical outcome of frozen cleaved embryos that were cultured to blastocyst after thawing in women with multiple implantation failures of embryo transfer: a retrospective study.
OBJECTIVE
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.


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 microm 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 microm 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.
Hiraoka
Kenichiro
K
Kinutani Women's Clinic, 8-23-4F, Hondori, Naka-ku, Hiroshima 730-0035, Japan. hiraoka@chive.ocn.ne.jp
Fuchiwaki
Megumi
M
Hiraoka
Kaori
K
Horiuchi
Toshitaka
T
Murakami
Tomoyo
T
Kinutani
Masayuki
M
Kinutani
Kazuo
K
D000328:Adult; D001755:Blastocyst; D002970:Cleavage Stage, Ovum; D015925:Cryopreservation; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D053685:Laser Therapy; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D046509:Tissue Culture Techniques; D017211:Treatment Failure; D015044:Zona Pellucida / Q000502:physiology*