Perinatal mortality in southern Brazil: a population-based study of 7392 births.

Perinatal, fetal and early neonatal mortality rates were determined in a population of 7392 babies born in hospitals in Pelotas (total population, 260 000) during 1982. These babies represented over 99% of all births in the city in that year. The perinatal mortality rate for singletons was 31.9 per 1000 total births, the fetal mortality rate being 16.2 and the early neonatal mortality rate 15.9 per 1000 total births.The most important variable influencing perinatal mortality was birth weight; low-birth-weight babies were 17 times more likely to die in the perinatal period than those weighing 2500 g or more. Perinatal mortality was also strongly influenced by socio-economic status, which was measured by family income. Babies belonging to the poorest families were 3 times more likely to die during the perinatal period than those in families with the highest incomes. Other variables significantly associated with perinatal mortality were gestational age, maternal age, maternal weight and height, reproductive history, attendance in antenatal clinics, parity, and birth interval. Information on most of these risk factors can easily be obtained by health workers at the beginning of pregnancy and should be taken into consideration when allocating women to the proper level of care.