Prevalence of small for gestational age newborns and associated factors in a Brazilian Northeast capital

Abstract Objectives: to analyze the factors associated with the birth of small for gestational age (SGA)infants, in a Northeastern Brazilian capital. Methods: a cross-sectional study was carried out with 331 pregnant women and their newborns attending the public health network in the city of Maceió, in 2014. Maternal antenatal data were collected (socioeconomic, lifestyle, clinical and nutritional) as well as data of the newborns (gestational age, mode of delivery, sex, birth weight and length), after delivery. Birth weight was classified according to the INTERGROWTH-21st curves, being considered SGA those below the 10th percentile according to gestational age and gender. The results were analyzed by Poisson regression using a hierarchical model and were expressed as prevalence ratios (PR) and their respective 95% confidence intervals (CI95%). Results: it was verified that 5.1% of the newborns were SGA. Regarding the associated factors, after adjustment of the hierarchical model, the variable working outside the home was associated with the endpoint studied [PR = 0.14; (CI95% = 0.02-0.75); p=0.022]. Conclusions: it was verified a low frequency of SGA infants in the evaluated population. The fact that the mother works outside the home proved to be a protective factor for this condition.