Human Fallopian tube epithelial cell co-culture increases fertilization rates in male factor infertility but not in tubal or unexplained infertility

In order to investigate the effect of human Fallopian tube epithelial cell co-culture on fertilization and cleavage rates in tubal, male and unexplained infertility, oocytes collected from 91 patients were randomized to wells containing Fallopian tube epithelial cell monolayers or conventional culture medium, and inseminated with spermatozoa. Fertilization and cleavage were assessed at 18 and 52 h, respectively. Co-culture significantly increased the fertilization rates over the control values in male infertility (41.67 versus 23.43%, P = 0.00005), but not in tubal infertility (69.33 versus 67.93%) or unexplained infertility (65.93 versus 54.36%). Cleavage rates were not different in co-culture and conventional in-vitro fertilization systems in any of the infertility subgroups. The number of blastomeres was significantly higher in the co-culture group on the day of embryo transfer (3.63 +/- 1.12 versus 3.04 +/- 1.26, P < 0.001). Pregnancy rates were similar in all infertility subgroups. There was no significant association between the number of co-cultured embryos transferred and the pregnancy, abortion and multiple pregnancy rates. It was concluded that human Fallopian tube epithelial cell co-culture clearly improves fertilization rates in male infertility but not in tubal or unexplained infertility. Improved fertilization rates in co-culture may be due to positive effect of co-culture on impaired sperm function.