Objective: To determine if embryos can modulate steroid hormone production by luteinized granulosa cells.
Design: Granulosa cells obtained from follicular aspirates were cultured alone or in the presence of a two-pronuclear zygote. The production of E2 and P by these cultures was evaluated by RIA.
Setting: In Vitro Fertilization Unit in an academic research environment.
Patients: Sixteen women undergoing IVF.
Interventions: Standard IVF-ET treatment cycle using leuprolide acetate for pituitary desensitization before hMG or urofollitropin for ovarian stimulation.
Main outcome measures: Estradiol and P concentration in culture media of luteinized granulosa cells alone or granulosa cells cocultured with a two-pronuclear embryo.
Results: Both E2 and P production by luteinized granulosa cells was reduced when cultured in the presence of an embryo.
Conclusions: Human embryos secrete a factor that regulates granulosa cell steroidogenesis.