This study examines risk factors for infant mortality using individual
-level data from a sample of parishes in northern Sweden in the ninete
enth century. Sweden is of particular interest because of its unusuall
y regular pattern of infant mortality decline during the century. We f
ollow a sample of women longitudinally through their successive pregna
ncies and observe the mortality experience of each child. Exploratory
and multivariate logistic regression analyses reveal an important intr
a-familial dimension to infant mortality that appears from the early s
tages of a woman's reproductive career. In addition, multivariate anal
yses by birth-order group suggest that ignoring intrafamilial correlat
ions of infant mortality may result in incorrect inferences. Siblings'
shared probabilities of dying as infants suggest that high-birth-orde
r children were not necessarily disadvantaged in any systematic way.