Objective: To evaluate the output of E2 and progesterone produced by cumulus cells, derived from mature and immature oocytes, in culture medium.
Design: Prospective randomized study.
Setting: McGill Reproductive Center, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.
Patient(s): Twenty-one women, <38 years of age and with normal menstrual cycles, who were undergoing intracytoplasmic sperm injection for assisted reproduction.
Intervention(s): Culture medium with or without fetal bovine serum (FBS) supplemented with either a physiologic (75 mIU/mL) or a supraphysiologic (7,500 mIU/mL) concentration of gonadotropins.
Main outcome measure(s): Comparison of steroid levels in culture medium.
Result(s): Estradiol secretion was significantly increased in the culture medium with FBS supplemented with both concentrations of FSH alone compared with control. However, E2 secretion was inhibited by both concentrations of FSH with LH. The level of E2 was undetectable in the medium without FBS even after supplementation with both concentrations of FSH alone, hCG alone, and FSH with LH. Progesterone production was increased in the medium with FBS supplemented with FSH alone, hCG alone, and FSH with LH compared with control. There was no difference in progesterone levels in the culture medium without FBS supplemented with both concentrations of FSH alone and hCG alone compared with control. However, progesterone secretion was increased in the medium without FBS supplemented with a physiologic concentration of FSH with LH.
Conclusion(s): Culture medium with FBS supplemented with a physiologic and a supraphysiologic concentration of FSH stimulates E2 secretion from cumulus cells derived from mature and immature oocytes. This suggests that it may be not necessary to add E2 to the culture medium for maturation in vitro of immature human oocytes retrieved from patients undergoing stimulated cycles.