Successful pregnancy after oocyte activation by a calcium ionophore for a patient with recurrent intracytoplasmic sperm injection failure, with an assessment of oocyte activation and sperm centrosomal function using bovine eggs  Yukihiro Terada, M.D., Ph.D., Hisataka Hasegawa, M.S., Aiko Takahashi, B.S., Tomohisa Ugajin, M.D., Nobuo Yaegashi, M.D., Ph.D., Kunihiro Okamura, M.D., Ph.D.  Fertility and Sterility  Volume 91, Issue 3, Pages 935.e11-935.e14 (March 2009) DOI: 10.1016/j.fertnstert.2008.09.043 Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

Figure 1 The microtubule (green) organization and DNA (blue) configuration of FF human oocytes after ICSI. Oocytes were judged as fertilization failed 30–48 hours after ICSI. We successfully analyzed 14 FF oocytes from these patients. Two oocytes were observed as category “A,” two oocytes were observed as category “B,” six oocytes were estimated as category “C,” and two oocytes were estimated as category “D.” It was difficult to classify the remaining two oocytes because a long time passed after ICSI and the ovum was extremely fragile. (A) The sperm nucleus seemed to be present outside of the cytoplasmic membrane (arrow), probably owing to a failed injection, and the oocyte had an intact M2 meiotic spindle. (B) The sperm nuclei were slightly decondensed (arrow) and inside the oocyte cytoplasm, and the oocyte had an intact M2 meiotic spindle. (C) The sperm nuclei showed a premature condensation of the chromosomes, and the oocyte had an intact M2 meiotic spindle. Interestingly, the sperm centrosome duplicated and organized a spindle around the male genome (arrow). (D) The oocyte was activated, forming 2PN; however, the pronuclear centration was arrested without a radial array of microtubules from the sperm centrosome (the “sperm aster”). This is a characteristic feature of the fertilization arrest that is caused by sperm centrosomal dysfunction. Bars = 10 μm. Fertility and Sterility 2009 91, 935.e11-935.e14DOI: (10.1016/j.fertnstert.2008.09.043) Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions