Zona-intact versus zona-free blastocyst transfer: a prospective, randomized study.
OBJECTIVE
To compare the outcome of zona-intact versus zona-free blastocyst transfer.


METHODS
Prospective, randomized study.


METHODS
Tertiary care private hospital IVF center.


METHODS
A total of 240 patients undergoing blastocyst stage ET (119 zona intact and 121 zona free).


METHODS
In vitro culture of embryos to the blastocyst stage was followed by random allocation to zona-intact or zona-free transfer.


METHODS
Treatment cycle characteristics, implantation, and pregnancy rates.


RESULTS
Transfer of zona-free blastocysts was associated with a higher implantation rate. Subgroup analysis, however, indicated that better outcome was achieved only in the group that received poor-quality blastocysts. Patients undergoing blastocyst transfer for the first time did not seem to benefit from zona-free blastocyst transfer.


CONCLUSIONS
Zona-free blastocyst transfer increases the success of blastocyst-stage transfer in patients with poor-quality blastocysts.
Assisted Reproduction Unit, American Hospital of Istanbul, Istanbul, Turkey. burman@superonline.com
Bulent
B
Urman
Basak
B
Balaban
Cengiz
C
Alatas
Senai
S
Aksoy
Alper
A
Mumcu
Aycan
A
Isiklar
D000328:Adult; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D011446:Prospective Studies; D015044:Zona Pellucida