Introduction. Human milk is an essential food for newborns and affects life in the long or short terms. Its composition is modified by nutritional status and maternal diet as well as by gestational age of the newborn. It provides human milk-fed infants with the medium-chain fatty acids which are a source of energy, and essential fatty acids and their metabolic derivatives which have been involved in the neural maturation. Objectives. Due to the fact that there is little local data concerning the fatty acid composition in human milk of pre-term and full-term newborns, the present study was carried out in women living in the urban area of the Buenos Aires Province. Materials and methods. Samples were provided by the Bank of Human Milk, H.I.G.A. San Martín Hospital. They corresponded to mothers who had delivered preterm infants (28-36 weeks of gestational age) or full-term infants (37-42 weeks of gestational ages). Total lipids were extracted, and the fatty acid composition was determined by gas-liquid chromatography. Results. Results showed increases in saturated fatty acids up to 14 carbon atoms and in polyunsaturated fatty acids in mothers of preterm newborns compared with those of full-term newborns. Conclusions. It can be concluded that gestational age affects human milk fatty acid composition. This food is essential for pre-term newborns as it is the source of energetic compounds (saturated fatty acids) as well as plastic compounds, (polyunsaturated fatty acids) which are essential for the synthesis of structural lipids and neural development.

RESUMEN Introducción. La leche materna es un alimento esencial para el recién nacido e influye en su calidad de vida en el corto y largo plazo. Su composición se modifica con el estado nutricional, la dieta materna y la edad gestacional del recién nacido. Entre otros nutrientes fundamentales provee a los lactantes de ácidos grasos de cadena media de fácil utilización, y de ácidos grasos esenciales y sus derivados metabólicos, en especial ácidos araquidónico y docosahexaenoico, que han sido involucrados en la maduración neural. Objetivos. Dada la escasez de datos locales se consideró la importancia de estudiar la composición en ácidos grasos de la leche de madres de recién nacidos de pretérmino y de término en mujeres del área urbana de la Provincia de Buenos Aires. Material y métodos. Las muestras fueron obtenidas del Banco de Leche Materna H.I.G.A San Martín. Se extrajeron los lípidos totales y se determinó la composición en ácidos grasos por cromatografía de gas-líquido. Resultados. Los resultados muestran aumentos en ácidos grasos saturados de hasta 14 átomos de carbono y en los ácidos grasos poliinsaturados en la leche de madres de recién nacidos de pretérmino con respecto a la de madres de recién nacidos de término. Conclusiones. La edad gestacional influye en la composición de los ácidos grasos de la leche materna, siendo la leche de madres de lactantes prematuros una fuente imprescindible de elementos energéticos (ácidos grasos saturados) y de elementos plásticos (ácidos grasos poliinsaturados) fundamentales para la síntesis de lípidos estructurales y en el desarrollo neural.

OBJETIVOS: avaliar as conseqüências para a mãe e para o filho do hábito de fumar durante a gestação. MÉTODOS: é um estudo prospectivo com 1.103 gestantes a partir de inquérito em mulheres atendidas no Hospital San Martin de La Plata, Buenos Aires. Amostras foram obtidas para determinação de elementos sangüineos e citometria de fluxo. O risco relativo entre fumantes e não fumantes foi calculado e se usou ainda o c² e o teste "t" de Student. RESULTADOS: 887 gestantes eram não fumantes e 226 não fumantes. O grupo fumante teve maior probalidade do que o não fumante para: partos prematuros, recém-natos com peso baixo, pequenos em relação à idade gestacional, maior risco de morte intra-uterina, Apgar abaixo de seis aos cinco minutos, síndrome da membrana hialina, menor número de consultas do que as programadas. A análise do sangue do cordão umbelical mostrou nas fumantes: menor número de reticulocitos, diminuição da relação CD4/CD8 e maior número de eritroblastos, eosinófilos, basófilos, linfócitos totais e CD8. CONCLUSÕES: os dados poderiam explicar observações de outros autores indicando maior incidência de alergias e infecções em recém-natos causadas por tabagismo materno.

OBJECTIVE: to evaluate the consequences of maternal smoking METHODS: a prospective study of 1.103 pregnant women. A survey in the state Hospital San Martin, de La Plata, Buenos Aires determined general data. Newborn and placenta data were also reported. Mother and child cord samples were obtained to determine blood elements and flow cytometry analysis of lymphocyte subsets performed. Data from smoking (S) and non-smoking (NS) groups were evaluated through relative risk, chi square and Student's t test. RESULTS: of all patients, 887 were NS and 226 said they smoked over five-cigarettes/day (S). The S group showed a higher probability of premature deliveries when compared to the NS group, with newborns weighing under 2,5kg, small in relation to gestational age, with Apgar scores at the 5th minute under six and hyaline membrane syndrome; intrauterine death risk was higher in this group who attended less medical appointments than scheduled. Umbilical cord blood analysis indicated lower reticulocyte index for S mothers, neutrophil count and CD4/CD8 ratio and increased erythroblast, eosinophil, basophil, total and CD8+T lymphocyte counts. CONCLUSIONS: data could explain the observations by other authors related to an increased incidence of allergy and infections in newborns caused by maternal smoking.