R. S. Jeyendran

Treatment of human spermatozoa with an egg yolk medium can enhance the outcome of in vitro fertilization

In at least 4 of 7 cases, fertilization of intact human oocytes was more successful when spermatozoa were pretreated with TEST yolk medium at 5 degrees C for 2 hours as compared with the standard treatment with Hams F-10 only. Both pregnancies that were obtained after the transfer of the fertilized oocytes resulted from oocytes fertilized by TEST yolk-treated spermatozoa. No decrease in fertilization occurred in any of the cases after TEST yolk treatment. If these results hold true for a larger series of patients, it may be worthwhile for the standard IVF incubation system of spermatozoa to include TEST yolk.

Nonbeneficial effects of glycerol on the oocyte penetrating capacity of cryopreserved and incubated human spermatozoa

The effect of cryopreservation on human spermatozoa in the presence or absence of glycerol was assessed by using sperm motility, functional integrity of sperm membrane, and denuded hamster oocyte penetration tests. Glycerol treated cryopreserved spermatozoa yielded a significantly higher (P less than 0.01) percentage of motile sperm and percentage of sperm with functionally intact membrane immediately after thawing than the spermatozoa not treated with glycerol but cryopreserved. However, no significant difference was observed between these cryopreserved spermatozoa (either treated or untreated with glycerol) on the percentage of motile sperm and the rate of oocyte penetration when the sperm were washed and incubated for 2 hr in a medium containing no glycerol. Thus, it appears glycerol may not be beneficial, since cryopreservation of spermatozoa either treated or untreated with glycerol essentially yields similar oocyte-penetrating capacity of sperm.

Morphometric and volumetric comparisons of human spermatozoa

Morphometric measures and volumes of spermatozoa were determined for 28 human ejaculates which were previously analyzed for semen volume, sperm concentration, morphology, motility, and fertility by in vitro fertilization procedures (IVF). Morphometric measurements of sperm heads were analyzed using a Zeiss Videoplan computer, while spermatozoan volume was determined with an Elzone particle analyzer. Though a strong relationship was anticipated, correlations between the volumetric data and different morphometric measures revealed poor, insignificant values. This lack of correspondence may be due to individual differences in the thickness of the spermatozoa within a sample. Twenty-two of the ejaculates used in this study were classified as fertile and six were infertile according to the IVF procedure results. Correlations between the morphometric measurements and the volume determinations in the fertile group were all positive. In contrast, those of the infertile group were all negative with one exception (width vs. volume).