Objective: To investigate protein and messenger RNA expression products for a subset of apoptosis-related genes in human granulosa cells. Design: In vitro experiment. Setting: Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Patient(s): Women undergoing oocyte retrieval for IVF after ovulation induction with gonadotropins. Intervention(s): Granulosa cells were isolated from follicular aspirates after oocyte removal. Main Outcome Measure(s): Reverse transcription polymerase chain reaction and Western blotting for apoptosis-related gene products. Result(s): The expression of caspase-1, caspase3, DNA fragmentation factor, and apoptotic protease activating factor-1, which are intermediate molecules in phylogenetically conserved apoptotic pathways, was demonstrated in granulosa cells from patients undergoing IVF. Moreover, proforms, but not activated enzymes, for both caspase-1 and caspase-3 were observed. Conclusion(s): Granulosa cells from patients undergoing IVF have intrinsic apoptotic machinery that could be activated for tissue remodeling. (Fertil Steril(R) 1998;70:549-52. (C) 1998 by American Society for Reproductive Medicine.).