Human pregnancies after transfer of fresh (four- to eight-cell) versus frozen-thawed blastocysts resulting from intracytoplasmic sperm injection.
OBJECTIVE
The objective of this study was to obtain expanded blastocysts following intracytoplasmic sperm injection (ICSI) and Vero-cell co-culture, cryopreserve them at this stage, and transfer the frozen-thawed blastocysts to obtain pregnancies.


METHODS
Twenty-two couples with severe male-factor infertility or failed fertilization in a previous in vitro fertilization cycle were included in this study. ICSI was performed for all of them, and sperm-injected oocytes were immediately subjected to Vero-cell co-culture for varying intervals. Then 14 couples were treated by embryo transfer at the four- to eight-cell stage (Group I), whereas 8 couples were treated by transfer of frozen-thawed blastocysts (Group II).


RESULTS
Percentages of cleaved embryos and term survival rates were 57.1 and 73.3% for Group I and 50.0 and 37.5% for Group II, respectively.


CONCLUSIONS
Blastocysts obtained after ICSI and Vero-cell co-culture can retain developmental competence after cryopreservation and thawing. Transfer of frozen-thawed blastocysts derived by these means holds promise for establishment of viable pregnancies.
Augusta Reproductive Biology Associates, Georgia 30904, USA.
E J
EJ
Servy
R A
RA
Kaufmann
Z
Z
Liu
Y
Y
Menezo
L
L
Keskintepe
D000328:Adult; D000818:Animals; D001755:Blastocyst; D002522:Chlorocebus aethiops; D018920:Coculture Techniques; D015925:Cryopreservation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007246:Infertility; D008297:Male; D009865:Oocytes; D011247:Pregnancy; D011256:Pregnancy Outcome; D013094:Spermatozoa; D014709:Vero Cells