Optimization and simplification of culture conditions in human in vitro fertilization (IVF) and preembryo replacement by serum-free media.

The results of 220 consecutive IVF treatments are presented, comparing the use of culture media supplemented with either patient serum (Group 1; n = 110), or Medi-Cult SSR 2 synthetic serum replacement with pyruvate, and human serum albumin (HSA) (GEA BioTech, Hvidovre, Denmark) (Group 2; n = 110). In both groups the Medi-Cult Hybritest was used for routine quality testing. A significantly (P less than 0.05) increased rate of deliveries/ongoing pregnancies was observed with the Group 2 medium. However, no significant differences in fertilization rate, cleavage rate, or implantation rate were observed. It is concluded that the serum-free culture medium described and the testing for absence of cytotoxicity in a sensitive bioassay (Hybritest) have yielded culture conditions capable of sustaining the development in vitro of human preembryos without impairing the fertilization process or the implantation rate, ultimately resulting in a significantly increased rate of deliveries/ongoing pregnancies and an apparently decreased abortion rate. The potential harmful effects of serum and the need for blood sampling and preparation further increase the advantages of replacing serum with the synthetic serum replacement SSR 2 in an IVF program.