title: Chromosome analysis of multipronuclear human oocytes fertilized in vitro.
abstract: In an in vitro fertilization and embryo transfer program composed mainly of patients with tubal infertility, the incidence of fertilized oocytes with multiple pronuclei was 4.3%. An attempt was made to fix such oocytes with supernumerary pronuclei in order to assess the chromosome constitution of the gametes. Nine multipronuclear oocytes containing a total of 29 pronuclei were successfully fixed before the first cleavage division, and another oocyte containing 3 pronuclei was fixed before the second cleavage division. On analysis, chromosome counts could be obtained for 28 of the 29 total pronuclei, and 24 gave informative results. Nineteen pronuclei had a normal haploid chromosome count, 2 pronuclei contained one extra chromosome, and 3 pronuclei had one chromosome missing. The presence of a Y chromosome in six pronuclei identified their paternal origin; two of the six sperm pronuclei had a 22,Y,-E chromosome constitution. Only three pronuclei could be conclusively ascertained to be maternal in origin, yet two of these were aneuploid; one pronucleus had a 24,X,+D karyotype and the second had only 22 chromosomes. Multipronuclear oocytes present ideal material for analyzing the chromosome constitution of those human gametes which can undergo fertilization in vitro.
mesh_terms: D000328:Adult; D002467:Cell Nucleus / Q000648:ultrastructure; D002869:Chromosome Aberrations; D002877:Chromosomes, Human; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy / Q000235:genetics; D007621:Karyotyping; D008297:Male; D008540:Meiosis; D009865:Oocytes / Q000166:cytology / Q000648:ultrastructure*; D011003:Ploidies; D013094:Spermatozoa / Q000648:ultrastructure