1 Pontifícia Universidade Católica do Rio Grande do Sul, Instituto do Cérebro do Rio Grande do Sul, Porto Alegre RS, Brazil.
2 Universidade do Vale do Taquari, Programa de Pós-Graduação em Biotecnologia, Lajeado RS, Brazil.
3 Concordia University, Faculty of Arts and Science, Department of Psychology, Montreal QC, Canada.
4 Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Medicina e InsCer, Disciplina de Neurologia, Porto Alegre RS, Brazil.

Background: Data on the outcomes of preterm newborns in South American countries are scarce. Given the great effect of low birth weight (LBW) and/or prematurity on children's neurodevelopment, it is extremely necessary to conduct studies on these phenomena in greater depth in more heterogeneous populations such as those ones from countries with limited resources.

Methods: We conducted a comprehensive literature search on databases including PubMed, the Cochrane Library, and Web of Science for articles published in Portuguese and English up to March 2021 involving children born and evaluated in Brazil. The analysis of the risk of bias was adapted from the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and used to evaluate the methodology of the included studies.

Results: From the eligible trials, 25 articles were selected for qualitative synthesis, and 5 of those, for quantitative synthesis (meta-analysis). The meta-analyses showed that children born with LBW presented lower scores on motor development when compared with controls (standardized mean difference: -1.15; 95% confidence interval [95%CI]: -1.56--0.73]; I²: 80%) and also scored lower in terms of cognitive development (standardized mean difference: -0.71; 95% CI: -0.99--0.44; I²: 67%).

Conclusion: The results of the present study reinforce that impaired motor and cognitive functions can be a significant long-term outcome of LBW. The lower the gestational age at delivery, the higher the risk of impairment in those domains. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database under number CRD42019112403.