Effect of coculture on subsequent survival and implantation of cryopreserved human embryos.
OBJECTIVE
This retrospective analysis was designed to assess the performance of human embryos following cryopreservation based on whether they were originally developed in standard culture medium (65 cycles, 223 embryos) or cocultured on partial monolayers of bovine oviductal epithelial cells (63 cycles, 198 embryos). Embryo cryosurvival and implantation were compared between the study group and the contemporaneously match controls.


RESULTS
During a 2-year period when no factors of the cryopreservation program were altered, 63 transfers of 159 surviving thawed control cleavage-stage embryos (71.3% survival) that were 54% intact gave rise to 11 viable pregnancies (17.5%/ET), to yield an implantation rate of 6.9% per embryo. Sixty-three transfers of 147 thawed cocultured embryos (74.2% survival) that were 61% intact gave an implantation rate of 13.6% per embryo that was significantly higher than the control group (P < 0.05).


CONCLUSIONS
Coculture of embryos prior to cryopreservation does not appear to improve cryosurvival; however, it does improve implantation postthaw compared with embryos following standard culture prior to cryopreservation.
Tucker
M J
MJ
Reproductive Biology Associates, Atlanta, Georgia 30342, USA.
Kort
H I
HI
Toledo
A A
AA
Morton
P C
PC
Wright
G
G
Ingargiola
P E
PE
Sweitzer
C L
CL
D000818:Animals; D002417:Cattle; D018920:Coculture Techniques; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology*; D004847:Epithelial Cells; D005187:Fallopian Tubes / Q000166:cytology; D005260:Female; D006801:Humans; D012189:Retrospective Studies