Polynuclear fertilization in various stimulation protocols in in vitro fertilization.
OBJECTIVE: To investigate the effect of some clinical characteristics, especially various ovarian stimulation protocols, on the occurrence of polypronuclear fertilization. METHODS: One hundred forty-eight consecutive cycles in 121 patients were treated in our IVF program and 735 oocytes were analyzed retrospectively. RESULTS: Multipronuclear fertilization occurred in 33 of 530 fertilized oocytes, an incidence of 6.2%. No significant difference in the incidence of polyploidy was observed between the three stimulation protocols (CC/hMG, hMG, GnRHa/hMG). Number of polypronuclear embryos was found to be correlated with the fertilization rate, concentration of sperm inseminated, and maturity of the oocytes. CONCLUSIONS: The maturity of the oocytes and the sperm fertilizing capacity should be examined to reduce the incidence of polypronuclear fertilization.