Factors associated with low birth weight at term: a population-based linkage study of the 100 million Brazilian cohort

Abstract

Background Factors associated with low birth weight at term (TLBW), a proxy for intrauterine growth restriction (IUGR), are not well-elucidated in socioeconomically vulnerable populations. This study aimed to identify the factors associated with TLBW in impoverished Brazilian women. Methods Records in the 100 Million Brazilian Cohort database were linked to those in the National System of Information on Live Births (SINASC) to obtain obstetric, maternal, birth and socioeconomic data between 2001 and 2015. Multivariate logistic regression was performed to investigate associations between variables of exposure and TLBW. Results Of 8,768,930 term live births analyzed, 3.7% presented TLBW. The highest odds of TLBW were associated with female newborns (OR: 1.49; 95% CI: 1.47–1.50), whose mothers were black (OR: 1.20; 95% CI: 1.18–1.22), had a low educational level (OR: 1.57; 95% CI: 1.53–1.62), were aged ≥35 years (OR: 1.44; 95% CI: 1.43–1.46), had a low number of prenatal care visits (OR: 2.48; 95% CI: 2.42–2.54) and were primiparous (OR: 1.62; 95% CI: 1.60–1.64). Lower odds of TLBW were found among infants whose mothers lived in the North, Northeast and Center-West regions of Brazil compared to those in the South. Conclusion Multiple aspects were associated with TLBW, highlighting the need to comprehensively examine the mechanisms underlying these factors, especially in more vulnerable Brazilian populations, in order to contribute to the elaboration of health policies and promote better conditions of life for poor and extremely poor mothers and children.

Patterns and Determinants of Birth Weight in Term Babies Delivered at an Urban Multi-Specialty Private Hospital in Southern Nigeria. A Retrospective Cross-Sectional Study

“…The prevalence is; however, lower than 10.7% reported by Fayehun and Asa [12] among babies delivered in Nigerian Low birth weight was present in 3.4% of term babies studied. The prevalence is similar to those reported in Uganda (4.3%) [18] and Brazil (3.7%) [19]. The prevalence of low birth weight in the current study, is however, lower than what was reported by Fayehun and Asa (7.5%) [12].…”

Incidence and risk factors for term low birth weight babies in a tertiary care hospital in Kerala

“…The studies conducted in different countries on the incidence of TLBW showed that it is 3.7% in Brazil, 2% in China, 12% in Ethiopia, 10.6% in Pakistan, and 33.1% in rural Central India 33.1%. 11 In a study conducted in Jodhpur, the incidence of TLBW was 22.46%, which is very high compared to this study. 5 Maternal age, height, weight, parity, history of abortion, or infertility history were not showing any statistically significant association with TLBW in this study.…”

“…A study conducted in Brazil showed a significant association of TLBW with mothers' age in the age group, 35 to 49 years. 11 Some studies showed a significant association of LBW with the age of the mother. 12,16,17 A study conducted by Deka et al showed a significant association between LBW and the mother's weight, but the association with height was not statistically significant.…”

Prevalence and factors associated with low birth weight in full-term newborns

“…Definiu-se que o modelo hierárquico de análise do baixo peso em nascimentos a termo deveria considerar variáveis pertencentes a três eixos: proximal (idade materna, sexo do recém-nascido e ordem de nascimento); intermediário (idade gestacional no início do pré-natal e número de consultas de pré-natal) e distal (estado civil e escolaridade materna) (9) . Desse modo, a variável dependente do estudo foi o baixo peso ao nascer, definido como peso menor que 2.500g em nascimentos a termo (37 a 41 semanas e seis dias).…”