The use of synthetic culture medium and patient serum for human in vitro fertilization and embryo replacement

Abstract

The use of heat-inactivated patient serum as both fertilization and embryo replacement medium was compared in a prospective randomized study with a fully synthetic culture medium containing human serum albumin without serum addition (B₃ INRA Menezo). Another series of the author's IVF program was analyzed retrospectively when a commercially available synthetic medium with bovine serum albumin (B₂ INRA Menezo) or B₃, as mentioned above, was used without serum addition for fertilization but with 50–100% patient serum as embryo replacement medium. Fertilization rates were significantly higher in the synthetic culture media (70%) than in serum (57%). The rate of polyploid fertilization was significantly lowest in B₃ medium. There was a clear trend toward better pregnancy rates when high-percentage or 100% patient serum was used for embryo replacement, no matter if one, two, three, four or more embryos were replaced. We conclude that there should be no need for any kind of serum addition to fertilization media. The present study proves our previous observation that the use of serum seems to be beneficial as embryo replacement medium. This might well be explained by a “protein stick effect” due to the high macromolecular contents of serum rather than by viscosity measurements, since no significant increase in viscosity was observed when a high percentage of serum was added to culture media.