title: Multiple births associated with assisted human reproduction in Canada.
abstract: OBJECTIVE
  Assisted human reproduction has been associated with increased rates of multiple births. Data suggest that twins and higher order multiple pregnancies are at risk for pre- and postnatal health complications that contribute to stress on both the family and the Canadian health care system. No published Canadian data estimate the contribution of assisted human reproduction to multiple birth rates. This study was designed to determine the contributions of age and assisted human reproduction to multiple birth rates in Canada.
  
  
  METHODS
  We performed analyses of existing Canadian databases, using a mathematical model from the Centers for Disease Control and Prevention. More specifically, data from the Canadian Vital Statistics: Births and Stillbirths database were combined with data from the Canadian Assisted Reproductive Technologies Register collected by the Canadian Fertility and Andrology Society. Datasets were standardized to age distributions of mothers in 1978.
  
  
  RESULTS
  RESULTS suggest that in vitro fertilization, ovulation induction, and age each contribute more to the rates of triplets than to twins. As expected, the contribution of natural factors was higher to twins than to triplets.
  
  
  CONCLUSIONS
  These are the first Canadian data analyzed to separate and measure the contributions of age and assisted reproductive technologies to multiple birth rates. Our findings are important for guiding physician and patient education and informing the development of treatment protocols that will result in lower-risk pregnancies and improved long-term health for women and their offspring.
authors.affiliation: Department of Obstetrics and Gynecology, University of Ottawa, Ottawa ON.
authors.forename: Jocelynn L
authors.initials: JL
authors.lastname: Cook
authors.affiliation: Statistics Canada, Ottawa ON.
authors.forename: Leslie
authors.initials: L
authors.lastname: Geran
authors.affiliation: Statistics Canada, Ottawa ON.
authors.forename: Michelle
authors.initials: M
authors.lastname: Rotermann
mesh_terms: D002170:Canada; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects / Q000706:statistics & numerical data; D017048:Health Care Costs; D006801:Humans; D008423:Maternal Age; D010062:Ovulation Induction / Q000009:adverse effects / Q000706:statistics & numerical data; D010353:Patient Education as Topic; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects / Q000706:statistics & numerical data*; D012307:Risk Factors; D014310:Triplets; D014427:Twins