RESUMEN
OBJECTIVE: To develop a murine in vivo bioassay that is sensitive to inherent variability of hMG. DESIGN: Female F1 hybrid mice were mated after injection with fixed dosages of each of four lots of hMG. Oocytes/embryos were collected and monitored during 5 days of culture. Outcome measures were compared with retrospective outcomes of ovarian stimulation of women with the same hMG lots. The bioassay was then used to compare biopotencies of six different lots of hMG. SETTING: Center for assisted reproductive technology. INTERVENTIONS: None. PATIENTS: Outcomes of controlled ovarian stimulation and IVF were retrospectively analyzed from 43 patients. MAIN OUTCOME MEASURES: Numbers of oocytes/embryos recovered, numbers fertilized, and numbers progressing beyond fertilization. RESULTS: Differences in biopotencies of hMG lots in the murine in vivo bioassay were consistent with differences in outcomes of patients treated with the same hMG lots during controlled ovarian stimulation. Bioassay outcomes also differed between different lots of hMG. CONCLUSION: The bioassay described in this study is sensitive to between-lot differences in hMG that affect follicle recruitment and oocyte quality in women (and in mice). In this respect, the bioassay could be of value in screening hMG lots, before its exploitation in a patient population. One such application is explored.