Low versus high volume of culture medium during embryo transfer: a randomized clinical trial

The aim of this prospective randomized control trial was to evaluate if the use of two different volumes (20-25 vs 40-45 mu l) of media used for embryo transfer affects the clinical outcomes in fresh in vitro fertilization (IVF) cycles. In total, 236 patients were randomized in two groups, i.e., low volume group (n = 118) transferring the embryos with 20-25 mu l of medium and high volume group (n = 118) transferring the embryos with 40-45 mu l of medium. The clinical pregnancy, implantation, and ongoing pregnancy rates were compared between the two groups. No statistically significant differences were observed in clinical pregnancy (46.8 vs 54.3%, p = 0.27), implantation (23.7 vs 27.8%, p = 0.30), and ongoing pregnancy (33.3 vs 40.0%, p = 0.31) rates between low and high volume group, respectively. Higher volume of culture medium to load the embryo into the catheter during embryo transfer does not influence the clinical outcome in fresh IVF cycles.