Chromomycin A3 staining, sperm chromatin structure assay and hyaluronic acid binding assay as predictors for assisted reproductive outcome.

Functional sperm tests such as the sperm chromatin structure assay (SCSA), chromomycin A3 staining (CMA(3)) and hyaluronic acid binding assay (HBA) have been suggested as predictive tests of fertility in vitro. This study aimed to define the clinical role of these functional parameters in assisted reproduction in a prospective cohort study. Conventional sperm diagnosis (motility, morphology and concentration) as well as SCSA, CMA(3) and HBA tests were performed on 205 semen samples [74 IVF, 94 ICSI and 37 combined IVF/intracytoplasmic sperm injection (ICSI)]. Main outcome parameters were fertilization rate, clinical pregnancy rate and take-home baby rate. The study showed that each of the three functional sperm tests was related to one or more conventional and one or more functional sperm tests, indicating that spermatozoa from patients with abnormal conventional semen parameters have a higher likelihood for multiple functional abnormalities. Only SCSA and CMA(3) staining were shown to have a limited predictive value when IVF or combined IVF/ICSI was applied. The proposed threshold value of

Influence of freeze-thawing on hyaluronic acid binding of human spermatozoa.

Mature human spermatozoa have at least three specific hyaluronic acid (HA) binding proteins present on their sperm membrane. These receptors play a role in the acrosome reaction, hyaluronidase activity, hyaluronan-mediated motility and sperm-zona and sperm-oolemmal binding. Cryopreservation of spermatozoa can cause ultrastructural and even molecular damage. The aim of this study was to investigate if HA binding receptors of human spermatozoa remain functional after freeze-thawing. Forty patients were enrolled in the study. Semen samples were analysed before and after cryopreservation. Parameters analysed included concentration, motility, morphology and hyaluronan binding. Samples were frozen in CBS straws using a glycerol-glucose-based cryoprotectant. HA binding was studied using the sperm-hyaluronan binding assay. Freeze-thawing resulted in a significant decline in motility: the percentage of motile spermatozoa reduced from 50.6 to 30.3% (P < 0.001). HA binding properties of frozen-thawed spermatozoa remained unchanged after the freeze-thawing process: 68.5 +/- 17.1% spermatozoa of the neat sample were bound to HA, as were 71.3 +/- 20.4 of the frozen-thawed sample. This study indicates that freeze-thawing did not alter the functional hyaluronan binding sites of mature motile spermatozoa, and therefore will not alter their fertilizing potential.