ETHNIC DISPARITIES IN BIRTH WEIGHT AND PRENATAL CARE UTILIZATION IN ECUADOR, 2024.

Low birth weight is defined as a weight of less than 2,500 grams. It is one of the leading causes of infant morbidity and mortality; furthermore, in the long term, it contributes to the development of severe malnutrition, neurological disorders, respiratory complications, and immune deficiencies, as well as to increased costs for the national healthcare system. This is an observational, analytical, cross-sectional study. The data are drawn from the "Live Births 2024" administrative registry database, managed by Ecuador's National Institute of Statistics and Census (INEC), covering the period from January 1 to December 31, 2024. A majority of mothers (91.7%) identified as mestizo, followed by indigenous (6.1%), Afro-Ecuadorian (1.2%), and Montubio (1.0%). The lowest average birth weight was in the Indigenous population (3063.2 g) and the highest in the Afro-Ecuadorian population (3095.8 g). Furthermore, a modest positive statistical association was observed between the number of prenatal visits and birth weight (7.30 g per additional visit), which should be interpreted with caution given the cross-sectional design. The overall prevalence of low birth weight was 8.7%, ranging from 8.2% among Montubio to 10.1% among Afro-Ecuadorian newborns; after adjustment for sociodemographic covariates, indigenous ethnicity remained associated with higher odds of low birth weight relative to the mestizo reference group (adjusted OR 1.13), and Montubio ethnicity was associated with a significant reduction in mean birth weight only after accounting for geographic region. These findings highlight the importance of analyzing the various risk factors associated with low birth weight, including sociodemographic characteristics and prenatal care.