OBJECTIVE: This study assessed energy, macronutrient, and micronutrient intakes of adolescents in the first and second trimesters of pregnancy and investigated their association with the infant's birth weight. METHODS: This longitudinal study included 139 pregnant adolescents seen at the prenatal care clinic of a public maternity hospital. They were followed from the first trimester of pregnancy until hospital discharge after delivery. The participants answered a food frequency questionnaire in the first and second trimesters of pregnancy. Birth weight and gestational age were collected from the mothers' hospital records. The means and 95% confidence intervals were calculated. The residual method was used for adjusting nutrient intake according to total energy intake. The factors associated with birth weight were identified by multiple linear regression models. RESULTS: The mothers of infants with birth weight higher than 2500 grams had higher mean intakes of protein (p=0.02), lipids (p=0.02), saturated fatty acids (p=0.02) monounsaturated fatty acids (p=0.05), cholesterol (p=0.01), calcium (p<0.01), potassium (p=0.01), and phosphorus (p<0.01). According to the multiple linear regression models, gestational age at delivery (β=105.8; p<0.01), number of prenatal care visits (β=34.1; p=0.04), intake of polyunsaturated fatty acids (β=7.5; p=0.04), intake of omega-3 fatty acids (β=74.3; p=0.05), and cholesterol intake (β=0.4; p=0.04) were predictors of birth weight. CONCLUSION: The mother's dietary lipid profile was the main predictor of the infant's birth weight and the results suggest that nutritional follow-up should be included in the prenatal care routine.
Food consumption; Prenatal care; Pregnancy in adolescence; Birth weight
