Utilization of high-security straws for embryo freezing in an in vitro fertilization program: a prospective, randomized study.
OBJECTIVE
To compare the outcome of frozen-thawed ET cycles where embryos had been stored in conventional versus ionomeric resin-based, high-security straws (HSSs).


METHODS
Prospective, randomized study.


METHODS
Private assisted-reproduction unit.


METHODS
Three hundred and six freeze cycles, and 197 thaw cycles.


METHODS
Day 3 embryos (n = 1,268) were frozen, and 517 were thawed using HSSs. Alternately, day 3 embryos (n = 1,228) were frozen, and 505 were thawed using conventional straws.


METHODS
Cryosurvival, cleavage and morulae formation rates, and clinical pregnancy, implantation, and multiple pregnancy rates.


RESULTS
Although cycle characteristics did not show any differences, the cryosurvival rate was higher in the HSS group (94.7%) than in the conventional straw group (86%), as was the morulae formation rate (58.7% versus 42.7%). Despite a similar number of embryos being transferred, the clinical pregnancy rate (PR) was higher in the HSS group, but the difference lacked statistical significance (42.5% versus 31.2). Implantation rates (19.4% versus 11.4%) and multiple PRs (41.8% versus 16.6%) were significantly higher in the HSS group than in the conventional straw group.


CONCLUSIONS
High-security straws are high effective in human embryo cryopreservation, because they provide higher cryosurvival and implantation rates, as well as a lower risk of cross-contamination compared to conventional straws.
Balaban
Basak
B
Assisted Reproduction Unit, Vehbi Koc Vakfi American Hospital, Istanbul, Turkey.
Yakin
Kayhan
K
Isiklar
Aycan
A
Urman
Bulent
B
D000328:Adult; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000295:instrumentation*; D004622:Embryo, Mammalian; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate