title: Pronuclear zygote score following intracytoplasmic injection of hyaluronan-bound spermatozoa: a prospective randomized study.
abstract: The aim of this study was to determine whether the early stages of embryo development, as assessed by the zygote score (Z-score), could be influenced by the injection of spermatozoa that had been preselected on the basis of their binding to hyaluronic acid (HA). A total of 407 sibling metaphase II oocytes, belonging to 44 different patients, were injected in a prospective randomized way, with either hyaluronic acid bound (HA(+) ) or non-bound (HA(-)) spermatozoa. The fertilization rate (75-70%), the percentage of the different Z-scores (Z 1: 22-24%, Z 2: 22-22.5%, Z 3: 44- 45%, Z 4: 12-8.5%), the mean score of the transferred embryos (3.76 +/- 1.29, 3.78 +/- 1.1) and the number of embryos at the 4-cell stage 45 h after injection (77-76%) were not different between the two groups. The ongoing pregnancy rate in this study (>20 weeks of gestation) was 36.4% per replacement, the implantation rate 28% and the twin pregnancy rate 44% (7/16). Although binding to HA did not apparently influence the Z-score, this agent continues to be used for the immobilization of spermatozoa prior to injection, on the basis that it is a natural product that can easily be metabolized by the oocyte via normal biological mechanisms.
authors.affiliation: Fertilitätslabor Kinderwunschzentrum Kantonsspital, Baden AG, Switzerland. marc.vandenbergh@ksb.ch
authors.forename: Marc Jg
authors.initials: MJ
authors.lastname: Van Den Bergh
authors.forename: Mary
authors.initials: M
authors.lastname: Fahy-Deshe
authors.forename: Michael K
authors.initials: MK
authors.lastname: Hohl
mesh_terms: D002467:Cell Nucleus / Q000502:physiology; D010064:Embryo Implantation; D047108:Embryonic Development; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D013094:Spermatozoa / Q000187:drug effects*; D015053:Zygote / Q000502:physiology*
chemical_list: D006820:Hyaluronic Acid