Viability of Human Follicular Oocytes Collected from Unstimulated Ovaries and Matured and Fertilized in vitro

Abstract

Immature human follicular oocytes were collected from unstimulated ovaries, matured and fertilized in vitro and then transferred to patients with no ovarian dysfunction such as premature ovarian failure. From 11 1 consenting donors, 422 immature oocytes were collected from 97 ovaries between January 1990 and October 1991. The number of oocytes collected from ovaries and their development were recorded so that comparisons could be made among donors of different ages and ovarian condition, such as menstrual cycle, cyclic and non-cyclic ovaries. The rate of fertilization in vitro showed a peak in the 31-40-year age group; however, there was no statistical difference in the rate of oocyte maturation and cleavage among the donors in the different age groups. Immature oocytes of the luted phase had a significantly higher maturation rate than those of the follicular phase. There was no significant difference in the number of recovered oocytes, or in the development of immature follicular oocytes, between cyclic and non-cyclic ovaries. Mature follicular fluid and peritoneal fluid had a significant effect on the development of immature follicular oocytes. Also, it was found that fertilized eggs cleaved more frequently in the medium containing hypoxanthine compared with the medium without hypoxanthine. Finally, from 21 transfer cycles, viable embryos were derived from immature follicular oocytes, resulting in two pregnancies, both leading to the birth of normal babies. These findings suggest that culture in vitro of immature follicular oocytes, from unstimulated ovaries, to a suitable condition, could be used optimally for clinical applications such as human ovum donation programmes.