Relationships between polypronuclear fertilization and follicular fluid hormones in gonadotropin-treated women.

Similar incidences of congenital abnormalities in in vitro fertilization and embryo transfer (IVF-ET) pregnancies and births in the general population have not supported earlier concerns that IVF may increase chromosomal aberrations. Nevertheless, polypronuclear fertilization is a common, undesirable, and poorly understood outcome of IVF. We evaluated hormone levels in 20 follicular fluids that were associated with mature oocytes that have fertilized abnormally (greater than or equal to pronuclei) and compared them to follicles with mature oocytes that cleaved normally, fertilized but failed to cleave, or did not fertilize. Progesterone (P), androstenedione, estradiol, percent free estradiol, sex hormone-binding globulin, insulin, and prolactin were measured. P levels were significantly higher in follicular fluids associated with oocytes that fertilized abnormally than in the other groups. Levels of the other hormones were similar in all the study groups. We conclude that IVF of oocytes from highly luteinized follicles as judged by P levels may result in polypronuclear fertilization.