Fatores associados à prematuridade e ao baixo peso ao nascer em Governador Valadares, Minas Gerais: estudo caso-controle

Abstract

Preterm birth and low birth weight are complex public health problems, as it involves a multifactorial etiology that interrelates and may vary across different populations and regions. The aims of this study were to verify the association of socioeconomic, demographic, environmental, reproductive, behavioral, health care and biological factors with preterm birth and low birth weight in live born children at the Governador Valadares hospital, in Minas Gerais State. Case-control study, conducted with live born children, from May 2017 to July 2018, whose mothers lived in the Governador Valadares municipality or region. The study population was divided into two groups: Premature Group and Low Birth Weight Group. The Premature Group, were composed by preterm live born and controls that were born at term and with adequate birth weight. In the Low Birth Weight Group, the cases were children born with low birth weight and controls with adequate birth weight. All controls were matched for gender and date of birth and for each case two controls were selected. Participated in this study, in the Premature Group, 221 cases and 442 controls, and in Low Birth Weight Group, 65 cases and 130 controls. After the adjusted analysis for the other factors of the study, it was found that the highest risks of preterm birth are associated with nulliparous (OR = 2.994; 95%CI =1.911-4.690; p < 0.001), multiple gestation (OR = 26.371; 95%CI =8.257-84.225; p < 0.001), higher incomes (OR = 2.091; 95%CI =1.341-3.262; p = 0.001), previous preterm birth (OR = 5.603; 95%CI =2.633-11.924; p < 0.001), violence against women (OR = 2.177; 95%CI =1.088-4.358; p = 0.028) and gestational diabetes (OR = 3.924; 95%CI =1.622-9.494; p = 0.002), preeclampsia/eclâmpsia (OR = 7.692; 95%CI =2.917-20.285; p < 0.001), urinary tract infection (OR = 1.999; 95%CI =1.305-3.031; p = 0.001), early membrane rupture (OR = 3.030; 95%CI =1.257-7.307; p = 0.014), vaginal bleeding (OR = 2.574; 95%CI =1.528-4.335; p < 0.001) and oligohydramnios (OR = 4.369; 95%CI =1.896-10.066; p = 0.001). Mothers who had six or more number of prenatal care appointments (OR = 0.345; 95%CI =0.221-0.539; p < 0.001) and who had anemia (OR = 0.349; 95%CI =0.213-0.571; p < 0.001) had a lower risk of being premature births. The highest risks of low birth weight are associated with nulliparous (OR = 2.033; 95%CI =1.047–3.948; p = 0.036) and with live births whose mothers smoked during pregnancy (OR = 2.850; 95%CI =1.013-8.021; p = 0.047) and consumed the water supplied by the municipal services affected by the iron-ore mining dam called Fundão collapsed, in Mariana (OR = 2.444; 95%CI =1.203–4.965; p = 0.013). Preterm birth is associated with economic, behavioral, reproductive, biological and health care factors, and many factors are considered preventable. Water consumed during pregnancy, primiparity and maternal smoking were associated with low birth weight in the population studied. This research was important for health professionals and managers to know the main factors associated with preterm birth and low birth weight that affect this region, with the purpose of adapting gestational care in detecting and preventing health problems, and thus, contribute to the reduction of preterm birth, low birth weight and neonatal morbidity and mortality.