bstet Am J Public Health. 2002 Aug;92(8):1323-30.
The impact of the increasing number of multiple births
on the rates of preterm birth and low birthweight: an
international study.
Blondel B, Kogan MD, Alexander GR, Dattani N, Kramer MS,
Macfarlane A, Wen SW.
Epidemiological Research Unit on Perinatal Health and
Women's Health, National Institute for Health and
Medical Research, Villejuif, France. blondel@vjf. Inserm.fr
Objectives:
We studied the effects of twins and triplets
on perinatal health indicators in the overall population
in the 1980s and 1990s in Canada, England and Wales,
France, and the United States.
Methods:
Data were
derived mostly from live birth registration. We used
rates, relative risks, and population attributable risks
for twins and triplets separately.
Results:
In each
country, the increase in multiple births, and the
increase in preterm delivery among multiple births,
contributed almost equally to the rise in or
stabilization of the overall rates of preterm delivery.
Twins contributed a much larger proportion of the
preterm deliveries and low-birthweight newborns than did
triplets.
Conclusions:
Twins have a major
population-based impact on the trends of perinatal
health indicators.