Fatores nutricionais e comportamentais maternos e o baixo peso ao nascer

Abstract

Birth weight is an important predictor of early newborn death, morbidity and long-term health outcomes. Every year approximately 20 million babies are born worldwide weighing less than 2.5 kg. In Brazil, 8.49% of babies born in 2017 exhibited low birth weight. The aim of this study was to identify the maternal nutritional and behavioral factors associated with low birth weight. Method: This is a retrospective case-control study using part of the database of the paper entitled “Low-dose calcium supplementation to prevent preeclampsia”, with data collected at public maternity wards in Manaus, Amazonas state between 2014 and 2018. The data of 958 women were analyzed, 71 of whom were allocated to the case group along with their low birth weight babies (<2500g) and 887 with newborns weighing ≥2500g assigned to the control group. The following variables were assessed: socioeconomic, demographic, obstetric, behavioral, nutritional and dietary data of the mother and characteristics of the newborn. The chi-squared test was used to analyze the relationships between the outcome variable and the others, considering p< 0.05 as statistically significant. The association between low birth weight and the independent variables was analyzed using logistic regression and a 95% confidence interval, and expressed by the odds ratio (OR). For multiple logistic regression, p<0.20 was adopted as entry criterion and p<0.05 to remain in the final model. Results: The prevalence of low birth weight was 7.41%, with the chances of delivering a low birth weight approximately twice as high among nulliparous women (ORa=1.91; 95%CI=1.00-3.66), 5 times greater in women that had 3 or fewer prenatal visits (ORa= 5.35; 95%CI= 2.02-14.17) and around 72-fold higher for those who gave birth before 37 weeks of gestation (ORa= 72.92; 95%CI= 33.91-156.79). In addition, the likelihood of low birth weight declined when the mother was overweight before pregnancy (ORa=0.40; 95%CI= 0.19-0.82). Conclusion: This study showed that the independent predictors of low birth weight are parity, number of prenatal visits and gestational age.