title: Initial IVF-ET experience with assisted hatching performed 3 days after retrieval followed by day 5 embryo transfer.
abstract: OBJECTIVE
  To report our initial IVF-ET experience combining assisted hatching performed 3 days after oocyte retrieval with day 5 embryo transfer (ET).
  
  
  METHODS
  Retrospective review of 110 consecutive IVF cycles not involving donor oocytes, including 16 cycles that involved assisted hatching performed 3 days after oocyte retrieval in combination with day 5 ET.
  
  
  METHODS
  Academic teaching hospital IVF center.
  
  
  METHODS
  Eighty-six consecutive IVF patients undergoing ET.
  
  
  METHODS
  Assisted hatching using acid Tyrode's solution performed 3 days after oocyte retrieval in selected cases in combination with day 3 or 5 ETs.
  
  
  METHODS
  Clinical pregnancy rate per ET.
  
  
  RESULTS
  Of the 16 women undergoing day 5 ET following day 3 assisted hatching, 14 had a clinical pregnancy. These included 11 ongoing/delivered singletons and 2 ongoing/delivered twin pregnancies, neither of which was monochorionic. These clinical and ongoing/delivered pregnancy rates compared very favorably with those of 54% and 46%, respectively, for the 35 patients undergoing day 5 ETs without assisted hatching, even though the latter group appeared to be better IVF candidates based on the prognostic factors commonly used to predict success.
  
  
  CONCLUSIONS
  Our experience suggests that day 3 assisted hatching followed by day 5 ET may be a useful combination in selected patients. Although not seen in our small series, an increased risk of monochorionic pregnancies remains a theoretical concern when such a combination is used, since both assisted hatching and blastocyst transfers have been independently linked to an increased risk in some reports.
authors.affiliation: Department of Obstetrics-Gynecology, University of Rochester, Rochester, New York 14642, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Graham
authors.forename: K M
authors.initials: KM
authors.lastname: Hoeger
authors.forename: W R
authors.initials: WR
authors.lastname: Phipps
mesh_terms: D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007231:Infant, Newborn; D017063:Outcome Assessment, Health Care; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D014430:Twins, Monozygotic