title: One versus two embryo transfer after IVF and ICSI: a randomized study.
abstract: BACKGROUND
  The main reason for adverse treatment outcome in assisted reproduction is the high rate of multiple pregnancies. The only strategy to avoid dizygotic twins is to transfer one embryo at a time.
  
  
  METHODS
  A total of 144 women, who had had at least four good quality embryos available after IVF/intracytoplasmic sperm injection (ICSI) and who had no more than one previous failed treatment cycle, were randomized to have either one or two embryos transferred. The treatment outcomes including those after frozen embryo transfer were compared between these groups.
  
  
  RESULTS
  The clinical pregnancy rate per transfer was 32.4% in the one embryo transfer group and 47.1% in the two embryo transfer group, the difference being not significant. Eleven twin deliveries (n = 39) occurred in the two embryo transfer group and there was one pair of monozygotic twins in the one embryo transfer group. The cumulative pregnancy rate per patient after transfer of fresh and frozen embryos was 47.3% in the one embryo transfer group and 58.6% in the two embryo transfer group.
  
  
  CONCLUSIONS
  Our results indicate that among women who have good quality embryos in their first IVF/ICSI, good treatment results can be achieved. They support the idea of changing embryo transfer policy towards one embryo transfer without any remarkable decrease in the success rate, while dizygotic twins can be avoided.
authors.affiliation: Department of Obstetrics and Gynecology, Oulu University Central Hospital, Oulu, Finland. hmartika@cc.oulu.fi
authors.forename: H
authors.initials: H
authors.lastname: Martikainen
authors.forename: A
authors.initials: A
authors.lastname: Tiitinen
authors.forename: C
authors.initials: C
authors.lastname: Tomás
authors.forename: J
authors.initials: J
authors.lastname: Tapanainen
authors.forename: M
authors.initials: M
authors.lastname: Orava
authors.forename: L
authors.initials: L
authors.lastname: Tuomivaara
authors.forename: S
authors.initials: S
authors.lastname: Vilska
authors.forename: C
authors.initials: C
authors.lastname: Hydén-Granskog
authors.forename: O
authors.initials: O
authors.lastname: Hovatta
mesh_terms: D000328:Adult; D015925:Cryopreservation; D036861:Delivery, Obstetric; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic; D016896:Treatment Outcome; D014427:Twins; D014430:Twins, Monozygotic