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.

In Vitro Oocyte Maturation and Preantral Follicle Culture from the Luteal-Phase Baboon Ovary Produce Mature Oocytes

“…Because progesterone concentration is high during pregnancy, the hormonal milieu prior to delivery resembles the luteal phase of the menstrual cycle. Other investigators subsequently proved that human immature oocytes retrieved during the luteal phase could be matured in vitro [8,10,46], with two four-cell embryos obtained in one study [46]. In the current study, baboon oocytes collected from small antral follicles during the luteal phase could mature in vitro and produced embryos that underwent normal early development.…”

“…However, this dogma is challenged by several recent studies. Two early studies reported that immature oocytes obtained from women undergoing cesarean section could be matured and fertilized in vitro [10,12]. Because progesterone concentration is high during pregnancy, the hormonal milieu prior to delivery resembles the luteal phase of the menstrual cycle.…”

“…Few data indicate whether primate immature oocytes retrieved during the luteal phase can undergo IVM and fertilization and produce viable embryos. Only a few studies describe luteal-phase-like oocyte retrieval performed during cesarean section; these studies reported that immature oocytes recovered during gynecologic surgery could be matured in vitro and fertilized [10][11][12]. Although a high concentration of circulating progesterone is present during pregnancy, this environment does not recapitulate the ovarian hormonal environment during the luteal phase.…”

Luteal phase oocyte retrieval and in vitro maturation is an optional procedure for urgent fertility preservation

“…Oocytes retrieved in the luteal phase were shown to have significantly higher maturation rates than those retrieved during the follicular phase (23). One study using a bovine model showed that maturation and fertilization rates were equal when compared with luteal oocyte retrieval (24).…”

Follicle environment and quality of in vitro matured oocytes

“…It is interesting to go back to the early studies which can for example support the value of IVM using oocytes from luteal phase [41]. Since then, several experiments have used immature GVstage oocytes collected at the same time as mature oocytes following COS.…”