RESUMO
An institution-based surveillance and nested case-control study was conducted in Natal, Northeastern Brazil to estimate the level and determinants of early neonatal mortality. The early neonatal mortality rate was 25.5 per 1000 live-birth, 75% of early neonatal deaths were premature low birthweight infants, and the mortality rates were 591 and 318 per 1000 respectively, for preterm small for gestational age (PT-SGA) and preterm appropriate for gestational age (PT-AGA) infants. Mortality was 50 per 1000 for term low birthweight, and 8.6 for term normal birthweight AGA infants. In addition to prematurity and low birthweight, the main risk factors associated with early neonatal death were maternal smoking, complications during pregnancy or intrapartum, and inadequate antenatal care. The associations were weaker for prepregnancy factors such as single marital status or low maternal body weight, and no significant associations were observed with socioeconomic status. These findings suggest that in this population, efforts to reduce early neonatal death should focus on improved maternal care and the prevention of prematurity.
PIP: To facilitate health service planning, a surveillance and case-control study were conducted of births in 3 hospitals and 2 maternity clinics in the city of Natal in northeastern Brazil. The surveillance study revealed 285 early neonatal deaths among the 111,171 singleton live births recorded in the study institutions from September 1984-February 1986, for a rate of 25.5/1000. 75% of these early neonatal deaths involved premature infants. The mortality rates were 591/1000 for preterm small-for-gestational age infants and 318/1000 for preterm appropriate-for-gestational age infants, while this rate was 50/1000 for term low-birthweight infants and only 8.6/1000 for term normal birthweights infants. The case-control study indicated that the maternal risk factors of body weight under 50 kg and single parent status significantly increased the likelihood of early neonatal mortality, while maternal age, parity, prior reproductive loss, and socioeconomic status did not have a significant effect on this outcome. Pregnancy-related factors that substantially increased the risk of early neonatal death included smoking, bleeding during the first or second trimester, toxemia, less than 5 prenatal care visits, and congenital malformations. These pregnancy-related risks exerted a more substantial effect than maternal characteristics, suggesting the feasibility of a strategy focused on preventing preterm births through prenatal care rather than a high-risk approach of screening women prior to pregnancy.