title: Live birth rate, multiple pregnancy rate, and obstetric outcomes of elective single and double embryo transfers: Hong Kong experience.
abstract: OBJECTIVE
  To compare the live birth rate, multiple pregnancy rate, and obstetric outcomes of elective single and double embryo transfers.
  
  
  METHODS
  Case series with internal comparisons.
  
  
  METHODS
  University affiliated hospital, Hong Kong.
  
  
  METHODS
  Between October 2009 and December 2011, 206 women underwent their first in-vitro fertilisation cycle. Elective single embryo transfer was offered to women who were aged 35 years or below, and had endometrial thickness of 8 mm or more and at least two embryos of good quality.
  
  
  METHODS
  Live birth rate, multiple birth rate, and obstetric outcomes.
  
  
  RESULTS
  Among the 206 eligible women, 74 underwent an elective single embryo transfer and 132 a double embryo transfer. The live birth rate was comparable in the two groups, being 39.2% in the elective single embryo transfer group and 43.2% in the double embryo transfer group, while the multiple pregnancy rate was significantly lower in the elective single embryo transfer group than the double embryo transfer group (6.9% vs 40.4%; P<0.001). Gestational ages and birth weights were comparable in the two groups. There was no significant difference between the two groups with respect to the rate of preterm delivery and antenatal complications (27.6% vs 43.9%, respectively; P>0.05).
  
  
  CONCLUSIONS
  In this selected population, an elective single embryo transfer policy decreases the multiple pregnancy rate without compromising the live birth rate. The non-significant difference in antenatal complications may be related to the small sample size.
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Joyce
authors: J
authors: Chai
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Tracy W Y
authors: TW
authors: Yeung
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Vivian C Y
authors: VC
authors: Lee
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Raymond H W
authors: RH
authors: Li
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Estella Y L
authors: EY
authors: Lau
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: William S B
authors: WS
authors: Yeung
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: P C
authors: PC
authors: Ho
authors: Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Ernest H Y
authors: EH
authors: Ng
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D018873:Pregnancy Rate; D011271:Pregnancy, Ectopic / Q000453:epidemiology; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D047928:Premature Birth / Q000453:epidemiology; D012189:Retrospective Studies
keywords: Birth rate; Embryo transfer; Pregnancy, multiple