title: Perinatal risk in singleton pregnancies after in vitro fertilization.
abstract: OBJECTIVE
  To assess perinatal risks to singleton births after in vitro fertilization (IVF) versus spontaneous conception.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  A 2006 registry database of the Japan Society of Obstetrics and Gynaecology (JSOG) capturing 5.8% of total births.
  
  
  METHODS
  53,939 singleton births from spontaneous conceptions and 1,408 singletons after IVF.
  
  
  METHODS
  None.
  
  
  METHODS
  Perinatal death, low-birth weight (LBW), small for gestational age (SGA), congenital malformation, and sex ratio assessment based on singleton birth cases versus singleton live-born cases.
  
  
  RESULTS
  In this study, IVF may include intracytoplasmic sperm injection (ICSI), gamete intrafallopian transfer, or IVF followed by zygote intrafallopian transfer. In crude and adjusted analysis, perinatal death, SGA, congenital malformation, and sex ratio were not statistically significantly associated with IVF. The LBW rates were statistically significantly higher in IVF pregnancies, but the association statistically significantly decreased after adjusting for confounding factors. Placental previa, a maternal outcome, was found to be statistically significantly higher in IVF pregnancies.
  
  
  CONCLUSIONS
  No evidence was implicated IVF procedures as dramatically increasing the adjusted risk of perinatal death, LBW, SGA, congenital malformation, or sex ratio when compared with spontaneous conceptions. However, because of sample size limitations, the study cannot exclude small to moderate increases in perinatal deaths or congenital malformations.
authors.affiliation: Department of Reproductive Health and Research, Family and Community Health Cluster, World Health Organization, Geneva, Switzerland. fujiim@who.int
authors.forename: Mai
authors.initials: M
authors.lastname: Fujii
authors.forename: Ryu
authors.initials: R
authors.lastname: Matsuoka
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bergel
authors.forename: Sheryl
authors.initials: S
authors.lastname: van der Poel
authors.forename: Takashi
authors.initials: T
authors.lastname: Okai
mesh_terms: D000328:Adult; D000465:Algorithms; D000013:Congenital Abnormalities / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007564:Japan / Q000453:epidemiology; D008297:Male; D009099:Multiple Birth Offspring / Q000706:statistics & numerical data; D007744:Obstetric Labor Complications / Q000453:epidemiology* / Q000401:mortality; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D056826:Single Embryo Transfer / Q000706:statistics & numerical data*