Comparative study on the use of human follicular fluid or egg yolk medium to enhance the performance of human sperm in the zona-free hamster oocyte penetration assay

Biological pH buffers in IVF: help or hindrance to success

PURPOSE

Minimizing environmental stress helps maintain cellular homeostasis and is a crucial component in optimizing embryo development in vitro and resulting ART success. One stressor of particular interest is pH. Biologic buffers, such as HEPES and MOPS, are valuable tools for stabilizing pH. The objective of this manuscript is to summarize efficacy and impact of various pH buffers used during IVF lab procedures

METHODS

Keyword searches were performed using Pubmed and Medline and relevant literature reviewed.

RESULTS

Various pH buffers have been used with varying degrees of success for gamete and embryo processing in a variety of animal species, as well as in human.

CONCLUSION

Though biologic buffers off a means to improve pH stability, not all buffers may be appropriate for use with gametes and embryos. Specific buffers may have undesired effects, and these may be buffer, species, cell type or concentration dependent. Continued research is needed to further refine and improve the use of biologic buffers for use in human ART.

Human serum and follicular fluid stimulate hyperactivation of human spermatozoa after preincubation

OBJECTIVE

To test the effects of steroid-containing media such as follicular fluid (FF) and serum and of steroid-free but human protein-rich medium on hyperactivation (HA) of human spermatozoa with and without a preincubation period.

DESIGN

Analysis of HA using a computer-aided sperm analysis system.

SETTING

Academic hospital and andrologic laboratory.

PATIENTS

Twenty-six sperm samples were obtained from 26 different IVF patients.

INTERVENTIONS

None.

RESULTS

After a preincubation period of 3 hours, FF and serum enhanced the HA after 1 hour. A human plasma protein-rich solution did not. Without preincubation, no stimulation of HA was observed.

CONCLUSION

Steroids may be involved in HA, and a preincubation period may be required for an appropriate FF-induced HA.