Received November 04, 2008
Accepted December 07, 2008

Objective: To assess post-thaw survival, implantation, and pregnancy rates of embryos derived from Intracytoplasmic Sperm Injection (ICSI) using fresh or cryopreserved ejaculated sperm. Methods: Post-thaw survival, implantation, and pregnancy rates were evaluated in 190 frozen–thawed embryo transfer cycles. The cycles were split into two groups: cycles in which fresh sperm were injected (n=150) and cycles in which cryopreserved sperm were used (n=40). Result(s): Among the frozen thawed embryos 355 were derived from ICSI cycles using fresh sperm and 81 embryos derived from ICSI cycles using cryopreserved sperm. The mean maternal age (33.34 ± 3.85 y-old and 34.03±6.09 y-old, P = 0.502), normal fertilization rate (77.1% and 76.7%, P = 0.911), mean number of embryos transferred pre-freezing (1.58±0.77 and 1.64±0.78; P = 0.716) or mean number of cryopreserved embryos (3.47±2.89 and 2.73±2.91, P = 0.173) were equal for cycles that used fresh or cryopreserved sperm respectively. It was not observed any influence of the use of frozen/thawed sperm for ICSI on the embryo quality prior freezing (RC=6.090. P=0.779), embryo survival (RC=2,584, P=0,635), implantation (RC=2.314, P=0.779), pregnancy (OR = 1.32; IC 95% = 0.55 – 2.67; P = 0.538) or miscarriage rates (OR = 0.85; IC 95% = 0.17 – 4.13; P = 0.837). Conclusion: Our findings indicate that the semen cryopreservation process does not impact in embryo survival rate and moreover, the clinical outcomes in embryo thaw cycles do not differ when fresh or thawed sperm are used.