Comparison of G1.2/G2.2 and Sydney IVF cleavage/blastocyst sequential media for the culture of human embryos: a prospective, randomized, comparative study

OBJECTIVE: To compare two commercially available sequential media, G1.2/G2.2 and Sydney IVF cleavage/blastocyst media, as supports for human embryo culture. DESIGN: Prospective randomized study. SETTING: University-based IVF clinic. PATIENT(S): Two hundred forty-nine patients undergoing IVF treatment for the first or second time, randomly allocated at the time of oocyte retrieval, to either culture in G1.2/G2.2 or Sydney IVF media. INTERVENTION(S): Oocyte recovery, IVF or intracytoplasmic sperm injection, embryo culture, transfer on day 3 or day 5/6. MAIN OUTCOME MEASURE(S): Developmental stage on day 3, blastocyst rate, pregnancy outcome as assessed by beta hCG positive test, implantation rates, and ongoing pregnancies. RESULT(S): Embryos cultured in G1.2/G2.2 media displayed a faster kinetics of cleavage, compaction, blastulation, and hatching, but a lower day 3 embryo quality than those grown in Sydney IVF media. For patients with at least five embryos, G1.2/G2.2 media yielded higher implantation rates (26.2%) in our day 3 embryo transfer program when compared to Sydney IVF medium (15.5%), whereas similar implantation rates were obtained for day 5/6 embryo transfer for both media (43.1% and 36.1%, respectively). CONCLUSION(S): In our day 3 embryo transfer program, G1.2/G2.2 media were superior to Sydney IVF media, whereas both media yielded similar outcomes in our blastocyst transfer program.