Factors Affecting Fecundability Trends Among Sperm Donors: A Multivariate Analysis

Artificial insemination (AI) with donor spermatozoa has been a routine assisted reproduction technique widely used for the treatment of infertile patients wishing to conceive in specific situations. In clinical treatment, we found that individual donors demonstrated differences among their fecundity. And there is significant deviation amongst pregnancy rates of AID as well. One of the important reasons that induce this difference is the individual variation of sperm donors. Thus, it is useful to analysis of the influence of factors affecting donors' fecundability.Objective: To evaluate the impact of factors affecting fecundity in order to provide valuable parameters for predicting donors' fecundability.Method(s): 1. retrospective study: We use the pregnancy rate (PR) to reflect the fecundability trends among sperm donors. (PR= number of pregnancy/ number of periodicity) On the basis of our hospital data base document, we selected clinical histories and computer registers of 50 frozen donor' semen and analyze the relationship between fecundity and the seminal routine parameters. 2. We determine the relationship between the fecundity and plasma membrane integrity, DNA fragment index, chromatin structure by Flow cytometry and fluorescence microscopy. Sperm plasma membrane damage is evaluated with Annexin-V binding, DNA fragmentation is measured with TUNEL technique, chromatin structure is assessed with SCSA detect.Result(s): 1. The percentage of normal morphology, post-thaw motility, post-thaw progressive sperm amount and the cryosurvival is directly correlated with the pregnancy rate. (P<0.01) There is significant deviation amongst different groups of the PR about these seminal parameters. 2. The percentage of PS translocation, apoptosis rate and DNA fragmentation is significantly correlated with the PR. (P<0.01) When the percent of Pi-negative spermatozoa >48.8% and DFI <7% in post-thaw sample, the fecundity of this sample is higher than others'.Conclusion(s): Both plasma membrane externalization of phosphatidylserine (PS) and DNA fragmentation can reduce the fecundability trends of sperm donors, however, these abnormalities can not be tested by seminal routine analysis. So seminal routine parameters are not reliable predictors of fecundity. Analyzing and predicting the donors' fecundability trends should consider the influence of sperm membrane integrity and DNA fragmentation.