Development of an effective and simple insemination method for the in vitro fertilization of patients with male-factor infertility.

An insemination method involving mechanical removal of the cumulus and multiple oocytes per dish (MRC-MOPD) was applied to achieve in vitro fertilization (IVF) of patients with male-factor infertility, and the prognosis of IVF and embryo transfer was evaluated. Although the fertilization rate of patients with male-factor infertility was only 41.4% (12/29) using standard insemination methods, a 73.0% (27/37) fertilization rate was achieved with the MRC-MOPD method. Moreover, 10 patients with male-factor infertility who were treated with the MRC-COPD method achieved clinical pregnancy. A comparison of the results in the 10 patients who were treated with both methods in common reveals that the MRC-MOPD method also increased the fertilization rate per oocyte. The rate of occurrence of polyploid fertilization did not increase, although large numbers of sperm were inseminated via the MRC-MOPD method. These results indicate that the MRC-MOPD method is an effective and simple insemination technique to achieve successful IVF of patients with male-factor infertility.