The value of oocyte reinsemination in human in vitro fertilization.

The value of oocyte reinsemination in human in vitro fertilization (IVF) was evaluated in this study. Two groups of 25 cycles each were studied. In group 1 cycles, insemination of mature/questionably mature oocytes (judged by cumulus and corona cell appearance) at 6.5 hours postcollection yielded a fertilization rate of 42.3%. This value was significantly lower than that obtained with reinsemination (70.8%). In group 2, questionably mature oocytes were treated as immature and inseminated 24 to 30 hours postcollection. The fertilization rate of mature eggs in group 2 was 68.2%, with a reinsemination success rate of 40%. Triploidy rates and cleavage rates of mature eggs, fertilized either at initial insemination or reinsemination and of fertilized immature eggs, were similar within group 1 and group 2 cycles. In group 1, two pregnancies resulted from transfer of embryos arising solely from successful reinsemination, with one infant delivered. These results indicate that reinsemination offers a useful adjunct for IVF in cases where fertilization failure occurs.