RESUMO
OBJECTIVE: This study aimed to assess the association between ultra-processed foods (UPF) consumption and some lifestyle factors during pregnancy and the baby's anthropometric measurements at birth. METHODS: Cross-sectional study conducted with immediate postpartum women and their babies. Food consumption during pregnancy was assessed retrospectively by a semi-quantitative food frequency questionnaire, and the baby's anthropometric measurements were obtained from the medical records. The percentual of energy from UPF was estimated, categorized in tertiles, and associated with the baby's anthropometric measurements using multinomial logistic regression, adjusting by maternal characteristics (per capita income, maternal age, gestational weight gain, parity, physical activity, and number of prenatal consultations). RESULTS: A total of 626 immediate postpartum women and their babies were evaluated. The mean percentual of energy from UPF consumption during pregnancy was 30.56%. Before adjustment, there was a greater chance of insufficient birth weight among babies of immediate postpartum women in the highest tertile of UPF consumption (OR 1.72; 95% CI 1.09-2.70; p = 0.020); however, such an association was not significant in the adjusted analyses. CONCLUSIONS: No association between UPF consumption during pregnancy and baby's anthropometric measurements at birth was observed, probably due to the multifactorial nature of anthropometry and the interference of sociodemographic, gestational, and environmental factors in the baby's health outcomes.