Proteomic characteristics of human sperm cryopreservation.

Human sperm cryopreservation in assisted reproductive technology is the only proven method that enables infertile men to father their own children. However, freezing and thawing reduces spermatozoon motility, viability, and fertilizing ability. An association between dysfunctional spermatozoa due to cryoinjury and protein changes has not been established. We investigated through proteomic analysis the differential protein characteristics between freeze-thawed and fresh sperm samples obtained from nine normozoospermic donors. Twenty-seven proteins differed in abundance between the two groups, and results were verified for four proteins via Western blot and immunofluorescent staining. These proteins are putatively involved in sperm motility, viability, acrosomal integrity, ATP and isocitrate content, mitochondrial membrane potential, capacitation, acrosome reaction, and intracellular calcium concentration. These marked differences suggest that dysfunctional spermatozoon after cryopreservation may be due to protein degradation and protein phosphorylation.

[Analysis of the pregnancy outcomes of 13 723 tubes of sperm specimens from the sperm bank].

OBJECTIVE: To investigate the safety of assisted reproductive technology (ART) with donated sperm from the sperm bank and the differences in the pregnancy outcomes of different means of promoting pregnancy. METHODS: We analyzed and compared the feedback data on promoting pregnancy with donated sperm from the sperm bank by artificial insemination by donor (AID), in vitro fertilization (IVF), and intracytoplasm sperm injection (ICSI). RESULTS: Totally, 13 723 tubes of sperm specimens were used for ART. The number of specimens used differed in different clinical reproductive centers, some using 1 tube and others using 2 tubes per cycle. The 13 723 tubes were used for a total of 7 743 cycles. Among the 7 123 cycles of AID, there were 1 415 clinical pregnancies (19.87%), 1 221 normal births (86.29%), 169 abortions (11.94%), 6 cases of birth defects (0.43%), 19 ectopic pregnancies (1.34%), and 0 sexually transmitted infection. Among the 571 cycles of IVF, there were 367 clinical pregnancies (64.27%), 330 normal births (89.92%), 35 abortions (9.54%), 0 birth defect, 2 ectopic pregnancies (0.54%), and 0 sexually transmitted infection. Among the 49 cycles of ICSI, there were 28 clinical pregnancies (57.14%), 25 normal births (89.29%), 3 abortions (10.71%), 0 birth defect, 0 ectopic pregnancy, and 0 sexually transmitted infection. There were statistically significant differences in the rate of clinical pregnancy among AID, IVF and ICSI (P < 0.05), but not between IVF and ICSI (P > 0.05), nor were there any significant differences in the rates of abortion, birth defects and ectopic pregnancy among AID, IVF and ICSI (P > 0.05). CONCLUSION: None of the recipients of the donated sperm from the sperm bank was infected with sexually transmitted diseases. AID, IVF and ICSI showed no significant differences from natural conception in the rates of abortion, birth defects and ectopic pregnancy. ART with donated sperm from the sperm bank is safe. IVF and ICSI are associated with a higher rate of pregnancy than AID, though the latter costs less than the former two.