Metaphase I oocyte maturation arrest 2017-09-22T02:21:05Z Oocyte arrest at metaphase I Failure of oocytes to proceed through the stages of meiosis with stoppage at the first metaphase stage. Metaphase I oocyte meiotic arrest Oocyte meiotic arrest at metaphase I An essential feature of successful mammalian reproduction is the fusion of a sperm with a metaphase II oocyte. Oocytes are first arrested at prophase I and resume meiosis in response to luteinizing hormone (LH). Following spindle assembly and extrusion of the first polar body, oocytes are again arrested at metaphase II until fertilization.Failure of oocytes to progress beyond metaphase I of meiosis. Oocyte maturation arrest