Determinants of perinatal and infant mortality in Italy.

Determinants of stillbirths, perinatal and infant mortality in Italy have been analyzed using information collected routinely by the Italian Central Institute of Statistics on more than 2,400,000 births and 33,000 infant deaths in the period 1980-1983. Individual records included data on maternal (i.e. age, education, obstetric history) and fetal characteristics (sex, birth weight, gestational week at birth). The Italian stillbirth, perinatal and infant (1st-365th day of life) mortality rates in the period considered were respectively 7.7/1000 births, 16.4/1000 births and 13.5/1000 livebirths. Perinatal and infant mortality was extremely elevated in the very-low-birth-weight category. About 90% of liverbirths weighing less than 1000 g died within the first year of life, but this fell to about 45% in babies weighing 1000-1499 g. Among other factors, stillbirth, perinatal and infant mortality rates were elevated among males, born to older women and in higher birth rank and multiple pregnancies. These findings persisted, although less markedly, after adjustment for weight. Mortality rates were about 50-70% higher in less educated women. This finding was not markedly changed after adjustment for birth weight and maternal age, suggesting that socio-economic factors are per se important determinants of perinatal and infant mortality in Italy.