Premature birth and associated factors in the Brazilian State of Santa Catarina: An analysis after alteration of the gestational age section of the Live Birth Declarations

Abstract

Objectives: to estimate the prevalence of premature birth and associated factors, after alteration of the gestational age section of Live Birth Declarations in the Brazilian State of Santa Catarina, in 2012. Methods: a cross-sectional study was carried out based on data from the Live Births Information System (SINASC). Prevalence rates for premature birth, raw and adjusted by Cox’s robust regression were calculated for the year 2012 and the results compared with those reported for 2005. Results: the prevalence of premature birth rose from 6.1%, in 2005, to 10.6% in 2012. Comparison of the two years found greater differences among non- Caucasian women and those with fewer prenatal consultations and a lower level of schooling. After adjustment for confounding factors, the prevalence of premature birth was found to be associated with a lower frequency of prenatal consultations (PR=2.64; CI95%: 2.58-3.28), lower levels of schooling (PR= 1.65; CI95%: 1.11-2.45), maternal age <20 years (PR= 1.24; CI95%: 1.17-1.31) and > 39 years (PR= 1.32; CI95%: 1.17-1.49) and non-Caucasian (PR=1.14; CI95%: 1.07-1.21.) Conclusions: changes in the gestational age section, now recorded as full weeks of gestation, have resulted in more reliable measurement of the prevalence of premature birth in Brazil.