Embryo culture media and IVF/ICSI success rates: a systematic review

BACKGROUND The media that are used to culture human preimplantation embryos are considered to be an important factor for the success rates of IVF/ICSI. Here, we present a systematic review of randomized controlled trials (RCTs) on the effect of culture media on IVF/ICSI success rates. METHODS RCTs published between January 1985 and July 2012 were eligible for inclusion. The primary outcome was live birth. Secondary outcomes were health of babies born, ongoing pregnancies, clinical pregnancies, miscarriages, multiple pregnancies, implantation rate, cryopreservation rate, embryo quality and fertilization rate. For those media that were evaluated in more than one comparison, an unconventional meta-analysis was performed by pooling the data of the media they were compared to. RESULTS Twenty-two RCTs were included that evaluated 31 different comparisons. Conventional meta-analysis was not possible for any of the outcomes as nearly all trials compared different culture media. Only four trials reported on live birth, and one of them reported a significant difference. Nine trials reported on ongoing and/or clinical pregnancy rates, of which four showed a significant difference. Pooling the data did not reveal a superior culture medium. CONCLUSIONS It is yet unknown what culture medium leads to the best success rates in IVF/ICSI. Given the potential importance of culture media for treatment outcome, rigorously designed RCTs are needed for currently available, as well as newly introduced culture media.