Establishment of a Latin American dataset to enable the construction of gestational weight gain charts for adolescents.

Gestational weight gain is an important indicator for monitoring nutritional status during pregnancy. However, there are no gestational weight gain references created for adolescents or national datasets to enable the construction of such graphs up to date. This manuscript aims to describe the creation of a Latin American dataset to construct gestational weight gain references for adolescents aged 10-19 years old. Gestational weight gain data from studies conducted in nine countries (Argentina, Brazil, Chile, Colombia, Mexico, Panama, Paraguay, Peru, and Uruguay) collected between 2003 and 2021 were harmonized. Data on height, weight, and gestational age in at least two gestational trimesters were included. Pregnant adolescents should be free of diseases that could affect weight, and newborns should weigh between 2,500-4,000 g and be free of congenital malformations. The final dataset included 6,414 individuals after data cleaning. Heterogeneity between the countries was assessed by calculating standardized site differences for GWG and z scores of height-for-age. Several imputation procedures were tested, and approximately 10% of the first-trimester weights were imputed. The prevalence of individuals with underweight (1.5%) and obesity (5.3%) was low, which may lead to problems when modeling the curves for such BMI categories. Maternal height and gestational weight gain did not show significant differences by country, according to the standardized site differences. A harmonized dataset of nine countries with imputed data in the first trimester of pregnancy was prepared to construct Latin American gestational weight gain curves for adolescents.