Relaxin secretion by human granulosa cell culture is predictive of in-vitro fertilization–embryo transfer success

We have developed a cell culture system for human luteinizing granulosa cells which supports the timely and dynamic secretion of oestrogen, progesterone and relaxin in patterns that mimic serum concentrations of these hormones during the luteal phase of the menstrual cycle. There was a wide variation in the amount of relaxin secreted by the cultured cells for the 69 patients studied. As relaxin production was generally maximal by day 10 of culture, comparisons were made at this time point. It was observed that most of the conceptions occurred in patients with higher relaxin secretion in vitro. All cycles with relaxin >800 pg/ml on day 10 had a term pregnancy while only 13% of cycles with relaxin