Background The rates of preterm birth have increased in many countries, including Canada, over the past 20 years.
However, the factors underlying the increase are poorly understood.
Methods We used data from the Statistics Canada live-birth and stillbirth data bases to determine the effects of changes in the frequency of multiple births, registration of births occurring very early in gestation, patterns of obstetrical intervention, and use of ultrasonographic dating of gestational age on the rates of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994.
All births in 9 of the 12 provinces and territories of Canada were included.
Logistic-regression analysis and Poisson regression analysis were used to estimate changes between the two three-year periods, after adjustment for the above-mentioned determinants of the likelihood of preterm births.
Results Preterm births increased from 6.3 percent of live births in 1981 through 1983 to 6.8 percent in 1992 through 1994, a relative increase of 9 percent (95 percent confidence interval, 7 to 10 percent).
Among singleton births, preterm births increased by 5 percent (95 percent confidence interval, 3 to 6 percent).
Multiple births increased from 1.9 percent to 2.1 percent of all live births ; the rates of preterm birth among live births resulting from multiple gestation increased by 25 percent (95 percent confidence interval, 21 to 28 percent). (...)
Mots-clés Pascal : Prématurité, Naissance, Epidémiologie, Etiopathogénie, Prévalence, Femelle, Canada, Amérique du Nord, Amérique, Homme, Appareil génital femelle pathologie, Gestation, Prévention
Mots-clés Pascal anglais : Prematurity, Birth, Epidemiology, Etiopathogenesis, Prevalence, Female, Canada, North America, America, Human, Female genital diseases, Pregnancy, Prevention
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0008218
Code Inist : 002B20F02. Création : 31/05/1999.