Reinsemination in human IVF with fresh versus initial semen: a comparative study.

In the event of non-fertilization of oocytes at the first insemination, repeat insemination is often successful in the IVF procedure. Nevertheless, the value of reinsemination is still controversial. In 56 out of 132 (42%) women treated in our IVF-ET Unit for mechanical infertility by identical induction and aspiration protocols, reinsemination of one or more ova was required. They were divided into two groups. Group I: 79 oocytes from 32 women who were reinseminated with initial semen 24 hours following primary insemination. Group II: 57 oocytes from 24 patients who were reinseminated with fresh semen 24 hours following primary insemination. Fertilization, cleavage and pregnancy rates differed significantly in group I as compared to group II (21.2%, 37.3%, p less than 0.005; 18.6%, 31.9%, p less than 0.001; 18.4%, 29.1%, p less than 0.001). We conclude that reinsemination is a beneficial procedure in cases of non-fertilization of oocytes at the first insemination. Furthermore, the use of fresh semen is preferred to achieve higher fertilization, cleavage and pregnancy rates.