title: Pregnancies from subzonal insemination of unfertilized oocytes after conventional IVF.
abstract: OBJECTIVE
  To evaluate the efficacy of subzonal insemination (SUZI) as applied to unfertilized oocytes after initial insemination.
  
  
  METHODS
  Unfertilized oocytes at metaphase II obtained after conventional IVF from 14 patients were selected for reinsemination by SUZI. The fertilization rate and pregnancy outcome were assessed.
  
  
  RESULTS
  Of the 57 unfertilized oocytes at metaphase II, 10 (17.5%) became fertilized after SUZI. Eight of the 10 (80%) oocytes showed normal fertilization with two pronuclei while the other two (20%) oocytes were polyspermic. Five (35.7%) of the 14 patients had embryo transfer resulting in two (14.3%) pregnancies. One patient had a spontaneous abortion and the other had a live birth at term.
  
  
  CONCLUSIONS
  Reinsemination of unfertilized oocytes by SUZI could be of value when fertilization fails after initial insemination.
authors.affiliation: Department of Obstetrics and Gynaecology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: E P
authors.initials: EP
authors.lastname: Loong
authors.forename: T T
authors.initials: TT
authors.lastname: Chiu
authors.forename: C J
authors.initials: CJ
authors.lastname: Haines
mesh_terms: D004624:Embryo Transfer; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D007315:Insemination, Artificial; D009865:Oocytes; D011247:Pregnancy