Abstract
Objectives: Hyaluronan, a high molecular weight glycosaminoglycan, is a major constituent of the cumulus oophorous matrix surrounding the human oocyte. During the process of fertilization, hyaluronan may play a critical role in the selection of functionally competent sperm. Huszar has demonstrated that specific motile sperm attach to a monolayer of hyaluronan immobilized on a surface and that such bound sperm demonstrate specific parameters of developmental maturity. Hyaluronan-bound (HB) sperm exhibit decreased levels of both cytoplasmic inclusions and residual histones, an increased expression of the HspA2 chaperone protein, and a marked reduction in the incidence of chromosomal aneuploidy. The relationship between HB sperm and enhanced levels of developmental maturity led to the current study of sperm binding potential and morphology. A pilot study was undertaken to explore the potential correlation between the ability of a seminal population to bind to the hyaluronan substrate and the Kruger Strict Criteria (KSC) morphological assessment demonstrated by the same population. Design: Excess semen samples from 31 infertility patients were assayed in the HYDAK(r) HBA chambers. Both normal and male factor patients were included. All specimens were analyzed for percent NSM using KSC. Two independent technicians performed each evaluation. Materials and Methods: Specimen collection, analysis and disposal followed a protocol approved by the Hospital Institutional Review Board. Hydak(r) HBA chambers, supplied by Biocoat, Inc., were fabricated from Cell-Vu(r) dual chamber disposable sperm counting slides. A molecular layer of hyaluronan was covalently bound to one chamber while the second counting chamber remained unmodified and served as a control. Following a 10-minute incubation period, the number of total, free motile and bound motile sperm were scored in each chamber. The HBA score was calculated as # bound motile sperm / # total motile sperm. Three morphology slides were prepared per patient and a minimum of 300 sperm were assessed using a 100X oil immersion lens and a calibrated reticle. A two-way contingency table evaluating the variables of NSM and HB was constructed to evaluate the data. Significance was tested by the Pearson Chi-squared statistic using SPSS for Windows software. Results: The analysis showed that fluctuations in NSM were statistically related to the ability of sperm to bind to hyaluronan (Chi squared = 8.16, p = 0.007, n = 31). Seminal populations demonstrating a NSM of <4% carried a mean HBA score of 44.4% (n = 13). In contrast, seminal populations carrying a NSM of >4% demonstrated a mean HBA score of 71.5% (n = 18). Conclusions: Hyaluronan may play a critical role in the selection of functionally competent sperm during in vivo fertilization. The current study demonstrated that a statistically significant relationship existed between the HBA and NSM carried by a seminal population. A seminal population carrying a higher HBA score was concomitant with increased levels of NSM. A lower HBA score was also found to be statistically consistent with poor morphology parameters. The HYDAK(r) HBA may therefore serve as a valuable diagnostic tool in assessing the level of developmental maturity, incidence of aneuploidy and morphological parameters of a seminal population. Ongoing studies are exploring the role hyaluronan may play in the selection of functionally competent sperm and the potential value of the HBA as a diagnostic tool.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call