Incidence and characteristics of insufficient birth weight newborns from a cohort ofneonates in a public regional hospital of a metropolitan area

Abstract

Introduction: birth weight is an indicator for the evaluation of intrauterine growth (IUGR) as well as a mortality risk index. There are already a large number of studies on newborns (NB) with low birth weight (LBW), while studies on those with insufficient birth weight (IB) are rare, including those related to adequate or limited intrauterine growth. Objective: to estimate the incidence of underweight among infants born at term and the proportion of those who are small for their gestational age, within an urban clientele of the Brazilian public health system, Sistema Único de SaÚde, SUS. Methods: observational study in a public maternity department of the hospital Regional de Cotia, in the metropolitan area of †São Paulo, which cares for of SUS patients. A universe of live births were evaluated in the last trimester of 2009, determining the proportion of IB infants and the adequacy of weight, based on gestational age and sex. Results: the incidence of insufficient birth weight was similar to that observed in the last two decades in Brazil, corresponding to 1/4 of the total number of births. The proportion of small gestational age newborns (NB SGA) was small, affecting only 4.2% of the IB infants. In 90% of these infants no pathology was identified to explain IB. The proportion of cesarean births (47.1%) among IB newborns as well as the difference in gestational age that they had in relation to the newborns of adequate weight, around four days, from the standpoint of IUGR does not justify the difference in mean weight between the two groups. Conclusion: the incidence of IB was high, however only a small proportion of these infants were small for gestational age. The data indicates the need for continued research on IB, including providing incentives for the continued improvement of public policies and programs regarding pre and peri-natal care.