Ganho de peso gestacional e desfechos neonatais adversos em duas cidades brasileiras: estimativa do efeito causal

Abstract

ABSTRACT Introduction: Despite the well-documented relationship between inappropriate gestational weight gain (GWG) and adverse neonatal outcomes, there are no studies that have estimated the causal effect of GWG on outcomes: preterm birth (PTB), small for gestational age (SGA) and large for gestational age (LGA). Objective: To verify the existence of a causal effect between GWG and adverse neonatal outcomes (SGA, LGA, PTB) in a cohort of two Brazilian cities. Methods: Retrospective cohort study nested in birth cohorts of São Luís-MA and Ribeirão Preto-SP conducted with 11,005 adult mothers with single live births between 24 and 43 incomplete weeks. GWG was categorized as inadequate, adequate and excessive, according to the recommendations of the Institute of Medicine in 2009. PTB was considered when gestational age was <37 weeks, SGA when weight for gestational age <p10 and LGA when> p90 on the INTERGROWTH-21st growth curve. The causal effect was estimated using the Propensity Score by inverse probability of treatment weighting adjusted for the variables indicated by the Directed Acyclic Graph. The variables were considered balanced according to the absolute standardized differences between the means and the variance ratios. Results: Pregnant women with inadequate GWG showed an increase in the probability of PTB (Coef = 0.07; 95% CI 0.05; 0.10; p <0.001) and SGA (Coef = 0.12; 95% CI 0.08; 0,15; p <0.001). On the other hand, pregnant women with excessive GWG showed an increase in the probability of LGA newborn (Coef = 0.14; 95% CI 0.11; 0.17; p <0.001). In all analyzes, all adjustment variables were balanced. Conclusion: Inadequate GWG is associated with adverse neonatal outcomes such as PTB and SGA. On the other hand, excessive GWG is associated with LGA, with an interpretation closer to causality, since the criteria for this were observed in this study.