In vitro deleterious effect of hypoxanthine in Ham's Nutrient Mixture F-10 culture medium on human oocyte fertilization and early embryonic development.

OBJECTIVE

To determine whether hypoxanthine in Ham's Nutrient Mixture F-10 (GIBCO, Grand Island, NY) culture medium affects murine embryo development or the outcome of patients undergoing IVF-ET.

DESIGN

For the two-cell embryo bioassay, embryos from each female were equally distributed and incubated in Ham's F-10 with or without hypoxanthine supplementation for up to 72 hours. To assess the effect of hypoxanthine in human IVF-ET, oocytes, sperm, and embryos were cultured in Ham's F-10 medium with or without hypoxanthine. Fertilization and embryo cleavage were assessed at 18 and 40 hours, respectively, after insemination.

SETTING

University medical research laboratory.

PATIENTS, PARTICIPANTS: Nine couples undergoing IVF-ET.

RESULTS

Two-cell mouse embryos incubated for 24 hours without hypoxanthine developed 40% to morula, compared with 6.5% for the hypoxanthine group. At 72 hours, 99.5% of the embryos without hypoxanthine reached the expanded blastocyst stage with 65% of them exhibiting hatching, compared with 72% and 19.5%, respectively, for the group with hypoxanthine. Human oocytes cultured in Ham's F-10 without hypoxanthine showed higher fertilization rates than the group incubated in the presence of hypoxanthine (69% versus 53%). The proportion of cleaved embryos was not different between the two culture media; however, the rate of embryos cleaving without cytoplasmic fragments was significantly higher in the group without hypoxanthine (75% versus 35%).

CONCLUSION

Ham's F-10 medium containing hypoxanthine significantly reduced embryo development in the two-cell mouse embryo bioassay. Hypoxanthine in culture medium for IVF-ET may have a deleterious effect on human gametes, leading to decreased fertilization and increased incidence of cytoplasmic fragments in the conceptuses.