title: Effects of in vitro fertilization on low birth weight, preterm delivery, and multiple birth.
abstract: OBJECTIVE
  To quantify the contribution of in vitro fertilization (IVF) on changes in the rates of low birth weight (LBW), preterm delivery, very low birth weight, and multiple births during the past 3 years.
  
  
  METHODS
  Data on IVF pregnancies from 1994 to 1996 within Alberta were reviewed. Population data were obtained from the Provincial notice of a live or stillbirth.
  
  
  RESULTS
  The IVF component of increased LBW rate in the province was 17.8% for infants <2500 g and 43.5% for those born <1500 g. IVF accounted for 10.5% of the provincial rate increase in deliveries <37 weeks' gestation and 66.2% of those <30 weeks' gestation. IVF accounted for 21.4% of the twins and all of the sets of triplets in the province.
  
  
  CONCLUSIONS
  During a 3-year period IVF has affected the incidence of LBW, preterm delivery, and multiple birth. IVF is a substantial contributor to changes in very low birth weight and delivery before 30 weeks, which is partly related to multiple births.
authors.affiliation: Division of Neonatology, Department of Pediatrics, Foothills Medical Centre, Calgary, Alberta, Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: Tough
authors.forename: C A
authors.initials: CA
authors.lastname: Greene
authors.forename: L W
authors.initials: LW
authors.lastname: Svenson
authors.forename: J
authors.initials: J
authors.lastname: Belik
mesh_terms: D000416:Alberta / Q000453:epidemiology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D011247:Pregnancy; D011272:Pregnancy, Multiple