Background:Optimal culture conditions are crucial for embryonic development and blastocyst formation after in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI). A prospective randomized trial was carried out to compare the effects of two different sequential media (Vitrolife and MediCult) on embryo development and implantation.Material/Methods: 176 couples were included in this prospective randomized study. All couples undergoing the IVF (n=84) or ICSI (n=92) program at the University of Würzburg were randomly assigned to either Vitrolife (n=87) or MediCult (n=89) sequential culture media.Results: The overall median fertilization rate (FR) was 84.0% and was similar in the Vitrolife (FR=87.5%) and MediCult group (FR=80.0%). A mean of 2.7 embryos were replaced into the uterus, not significantly different between both groups. The pronuclear development was significantly enhanced in embryos cultured in Vitrolife than in those cultured in MediCult media (p=0.035). The embryonic development on day 3 was also superior in the Vitrolife group, but only in ICSI cycles (p<0.01). After 5 days of culturing, the blastocyst development was equivalent in both groups. The clinical pregnancy rate was 31.0% per transfer in the Vitrolife group and 28.1% in the MediCult group (not significant).
Conclusions: The results demonstrate that implantation and clinical pregnancy rates with both media are comparable. Embryonic development until day three seemed to be enhanced when the embryos were cultured in Vitrolife media.

Keywords: Blastocyst - cytology, Culture Media, Embryo Transfer, Embryonic and Fetal Development, Fertilization in Vitro - methods, Pregnancy, Prospective Studies, Sperm Injections, Intracytoplasmic - methods, Zygote - growth & development, Blastocyst - cytology, Culture Media, Embryo Transfer, Embryonic and Fetal Development, Fertilization in Vitro - methods, Pregnancy, Prospective Studies, Sperm Injections, Intracytoplasmic - methods, Zygote - growth & development