The epidemiologic paradox of low birth weight in Brazil.
OBJECTIVE
To examine whether the low birth weight (LBW) paradox exists in Brazil.


METHODS
LBW and cesarean section rates between 1995 and 2007 were estimated based on data from SINASC (Brazilian Live Births Database). Infant mortality rates (IMRs) were obtained using an indirect method that correct for underreporting. Schooling information was obtained from census data. Trends in LBW rate were assessed using joinpoint regression models. The correlations between LBW rate and other indicators were graphically assessed by lowess regression and tested using Spearman's rank correlation.


RESULTS
In Brazil, LBW rate trends were non-linear and non-significant: the rate dropped from 7.9% in 1995 to 7.7% in 2000, then increased to 8.2% in 2003 and remained nearly steady thereafter at 8.2% in 2007. However, trends varied among Brazilian regions: there were significant increases in the North from 1999 to 2003 (2.7% per year), and in the South (1.0% per year) and Central-West regions (0.6% per year) from 1995 to 2007. For the entire period studied, higher LBW and lower IMRs were seen in more developed compared to less developed regions. In Brazilian States, in 2005, the higher the IMR rate, the lower the LBW rate (p=0.009); the lower the low schooling rate, the lower the LBW rate (p=0.007); the higher the number of neonatal intensive care beds per 1,000 live births, the higher the LBW rate (p=0.036).


CONCLUSIONS
The low birth weight paradox was seen in Brazil. LBW rate is increasing in some Brazilian regions. Regional differences in LBW rate seem to be more associated to availability of perinatal care services than underlying social conditions.
Silva
Antônio Augusto Moura da
AA
Departamento de Saúde Pública, Universidade Federal do Maranhão, São Luís, MA, Brasil. aasilva@elo.com.br
Silva
Leopoldo Muniz da
LM
Barbieri
Marco Antonio
MA
Bettiol
Heloísa
H
Carvalho
Luciana Mendes de
LM
Ribeiro
Valdinar Sousa
VS
Goldani
Marcelo Zubaran
MZ
D001938:Brazil / Q000453:epidemiology; D002585:Cesarean Section / Q000706:statistics & numerical data; D004522:Educational Status; D005260:Female; D006801:Humans; D007226:Infant Mortality / Q000639:trends*; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011247:Pregnancy; D015995:Prevalence