title: Prevention of multiple pregnancies by restricting the number of transferred embryos: randomized control study.
abstract: BACKGROUND
  The high incidence of multiple pregnancies is a major concern in the treatment of infertility by in vitro fertilization (IVF). Risks and costs are associated with multiple pregnancies and it is important to find a way to decrease multiple pregnancies. The standard protocol for IVF includes the transfer of two or three embryos.
  
  
  METHODS
  In this study, we compared the rate of single and multiple pregnancies between patients who received two and three embryos. One hundred and sixty-nine patients were randomly divided into two groups, with 106 cycles of IVF each. Group 1 received two embryos, and group 2 three.
  
  
  RESULTS
  Group 1 had total 40 (37.8%) pregnancies, while group 2 had 29 (27.4%). The number of ongoing pregnancies was 33 (31.1%) in group 1 and 26 (24.5%) in group 2. The number of baby-take-home was 32 (30.1%) in group 1 and 26 (24.5%) in group 2. These results show that there was no significant difference between the two groups in both the total and ongoing pregnancies. On the other hand, the number of twin pregnancies was 6 (15.0%) in group 1 and 12 (41.4%) in group 2, showing a significant difference. Group 1 had no triplet pregnancies, while Group 2 had two.
  
  
  CONCLUSIONS
  We conclude that the transfer of two embryos reduces the incidence of multiple pregnancies while maintaining an acceptable rate of pregnancy in IVF.
authors.affiliation: Department of Obstetrics and Gynecology, Hyogo College of Medicine, 1-1 Mukogawa-cho, 663-8501, Nishinomiya, Hyogo, Japan. komor615@hyo-med.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Komori
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kasumi
authors.forename: Isao
authors.initials: I
authors.lastname: Horiuchi
authors.forename: Yukari
authors.initials: Y
authors.lastname: Hamada
authors.forename: Chizu
authors.initials: C
authors.lastname: Suzuki
authors.forename: Minoru
authors.initials: M
authors.lastname: Shigeta
authors.forename: Koji
authors.initials: K
authors.lastname: Koyama
mesh_terms: D004624:Embryo Transfer / Q000592:standards*; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007246:Infertility / Q000628:therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple