Nicotinamide, a component of complex culture media, inhibits mouse embryo development in vitro and reduces subsequent developmental potential after transfer.

OBJECTIVE

To determine the effects of B-group vitamins present in culture media on mouse embryo development in vitro and subsequent viability.

DESIGN

Mouse zygotes were cultured in the presence of B-group vitamins. Embryo morphology and cell numbers were determined at 96 and 120 hours after hCG. Viability was assessed by transfer of embryos after 3 days of culture to pseudopregnant recipients. Resultant pregnancy rates (PRs) and fetal weights were determined.

RESULTS

Supplementation of an amino acid-free medium with minimal essential medium (MEM) B-group vitamins significantly decreased embryo cleavage rates, whereas the inclusion of Ham's F-10 medium B-group vitamins significantly reduced both cleavage rates and morphological development. Subsequent experiments determined that nicotinamide (5 microM) significantly reduced blastocyst cell number, implantation rate, viable PR, and fetal weight.

CONCLUSION

The data indicate that nicotinamide inhibits mouse embryo development in culture and reduces viability. Nicotinamide is present at high levels in Ham's F-10 and MEM media that are used routinely in human embryo culture. The role of vitamins in human embryo development in vitro warrants investigation.