Resumen: La nutrición post alta del prematuro debe evitar el incremento excesivo o insuficiente de peso, con un crecimiento óptimo de circunferencia craneana y talla. En Chile los prematuros < 32 semanas reciben fórmulas enriquecidas durante el primer año si no se alimentan con lactancia materna exclusiva. Objetivo: describir el crecimiento e identificar precozmente el riesgo de malnutrición a los 24 meses. Pacientes y Método: Estudio de cohorte retrospectivo del crecimiento desde el nacimiento hasta los 2 años de edad corregida, de prematuros < 32 semanas de edad gestacional. Se analizó puntaje Z de peso, longitud, perímetro craneano e índice de masa corporal (IMC). Se analizaron los factores asociados al IMC a los 2 años; IMC entre -1 y +1: eutrofia; > +1: riesgo de malnutrición por exceso; < -1 malnutrición por déficit. Resultados: Se reclutaron 996 prematuros, 559 cumplieron control a los 24 meses. 64,5 % eutrófico, 18,4% riesgo de malnutrición por exceso, 17,1% malnutrición por dé ficit. En el análisis multivariado, el riesgo de malnutrición por exceso se asoció al peso de nacimiento > 1.460 g: OR 5,77 (2,11-15,77) y Z IMC > 1,6 a 6 meses: OR 2,67 (1,91-3,74); la malnutrición por déficit se asoció a peso de nacimiento < 1.000 g: OR 3,1(1,1-8,8) y Z IMC < -0,75 a 6 meses: OR 8,2 (4,3-16,3). Conclusiones: El mayor riesgo de malnutrición por exceso y por déficit puede ser antici pado con el peso de nacimiento y Z IMC a los 6 meses de edad corregida.

Abstract: Post-discharge nutrition of preterm newborns must avoid excessive or insufficient weight gain and optimal length and head circumference growth. In Chile, premature infants less than 32 weeks at birth receive fortified formulas during the first year, unless they are exclusively breastfed. Objective: To describe growth and identify the risk of malnutrition at 24 months. Patients and Method: Retrospective cohort study that analyzes growth from birth to 2 years of corrected age in preterm patients < 32 weeks of gestational age. Z-score of weight, length, head circumference, and Body Mass Index (BMI) were analyzed. Factors related to Z BMI at 24 months were analyzed as follows: Eutrophic: Z BMI between -1 and +1; Overweight: Z BMI > +1; Underweight: Z BMI < -1. Results: 996 preterm infants were included, 559 completed check-ups at 24 months. 64.5% were eutrophic, 18.4% overweight, and 17.1% underweight. Multivariate analysis showed that risk of overweight was associated with birth weight > 1460 g: OR 5.77 (2.11-15.77) and Z BMI > 1.6 at 6 months: OR 2.67 (1.91-3.74); underweight risk was associated with birth weight < 1000g: OR 3.1 (1.1-8.8) and Z BMI < -0.75 at 6 months: OR 8.2 (4.3-16.3). Conclusions: The greater risk of overweight and underweight can be anticipated in premature infants under 32 weeks with birth weight or Z BMI at 6 months of corrected age.

Abstract: The growth of preterm newborns can be affected during the fetal period, hospitalization, and post discharge. Objective: to describe the anthropometric development of preterm newborns with or without intrauterine and postnatal growth restriction, and with or without recovery at 40 weeks from birth to 24 months of age. Patients and Method: Retrospective, descriptive study with Z-scores (Fenton and WHO) of weight, length, head circumference, and weight/length of preterm infants of less than 32 weeks of gestational age at birth up to 24 months of corrected age. 4 groups were defined ac cording to prenatal, postnatal, post-discharge growth as follows: Group AAA: newborns born AGA, with no postnatal growth restriction; Group APA: newborns born AGA, with postnatal growth restriction, weight < p10 at discharge, and weight > p10 at 40 weeks; Group APP: newborns born AGA, with postnatal growth restriction, weight < p10 at discharge and at 40w; and Group PPP: newborns born with intrauterine growth restriction and who maintained postnatal growth restriction (< p10 at birth, at discharge, and at 40w). We used descriptive statistics with ANOVA, Chi-squared, and linear mixed model analysis. Results: 710 preterm newborns were included, birth weight 1272 grams (SD 360) and gestational age 29 weeks (SD 1.9). Group AAA had weight, length, and head circumference Z-scores close to the median until 2 years of age. AGA preterm newborns and with postnatal growth restriction can evolve in two ways: one group presents recovery at 40 weeks (Group APA) while the other group presents weight Z-score < -1 up to 6 months (Group APP). Group PPP (with intraute rine and postnatal growth restriction) presents slow weight and length Z-score recovery, weight Z- score -2.3 at discharge, and slow improvement to < -1 at 2 years of age. All groups had weight/height Z-scores above the median in the first 2 months of corrected age. Conclusion: Preterm newborns with good fetal growth but restricted postnatal growth, may recover at 40 weeks, with subsequent normal development or recover at 6 months.

Resumen: Introducción: El crecimiento de recién nacidos prematuros puede afectarse durante período fetal, la hospitalización y post alta. Objetivo: describir el crecimiento de prematuros, con o sin restricción de crecimiento intrauterino y postnatal, y con o sin recuperación a las 40 semanas desde el nacimiento hasta los 24 meses de vida. Pacientes y Método: Estudio descriptivo retrospectivo de crecimiento en puntaje Z (según Fenton y OMS) de peso, longitud, perímetro craneano y peso/talla de prematuros < 32 se manas al nacer, hasta los 2 años de edad corregida. Se definieron cuatro grupos según crecimiento prenatal, postnatal y postalta. Grupo AAA: lactantes nacidos AEG, sin restricción postnatal; Grupo APA: lactantes nacidos AEG con restricción postnatal, con peso al alta < p10, y a las 40 semanas con peso > p10; Grupo APP: lactantes nacidos AEG, con restricción postnatal, con peso al alta < p10, que se mantienen bajo percentil 10 a las 40 semanas, y Grupo PPP: lactantes nacidos con restricción intrauterina y que mantuvieron restricción postnatal (al nacer, al alta y 40 semanas con peso < p10). Se utilizó estadística descriptiva, ANOVA y Chi cuadrado, y análisis de Modelos Lineales Mixtos. Resultados: Se incluyeron 721 prematuros, peso de 1272 g. (DE 360) y edad gestacional 29 (DE 1,9) semanas al nacer. El grupo AAA mantiene puntaje Z de peso, longitud y perímetro craneano alrededor de la mediana, hasta los 2 años. Los prematuros adecuados al nacer y restricción postnatal, pueden tener dos trayectorias: un grupo presenta recuperación a las 40 semanas (Grupo APA) y otro grupo presenta puntaje Z peso < -1 hasta los 6 meses (Grupo APP). El grupo PPP (con restricción intrauterina y postnatal) presenta lenta recuperación de puntaje Z de peso y longitud con Z de peso alta de -2,3 y lenta mejoría hasta < -1 a los 2 años. Todos los grupos presentaron Z peso/talla sobre la mediana en los primeros 2 meses corregidos. Conclusión: Los prematuros con buen crecimiento intrauterino en peso, pero deterioro postnatal, pueden recuperarse a las 40 semanas, con evolución normal posterior o recuperarse a los 6 meses. El grupo de prematuros con restricción de crecimiento pre y post natal (PPP) mantiene el compromiso nutricional en los 2 primeros años de vida.

OBJETIVO: Determinar a incidência de displasia broncopulmonar, os fatores de risco e a utilização de recursos em uma ampla população sul-americana de recém-nascidos de muito baixo peso ao nascer MÉTODOS: Dados prospectivamente registrados de crianças com peso ao nascer entre 500 a 1.500 g, nascidas em 16 centros neonatais pertencendo à rede NEOCOSUR entre 10/2000 a 12/2003. A análise multivariada de Poisson com variância robusta foi utilizada para determinar os fatores de risco relativo e intervalo de confiança de 95% que afetam o risco de apresentação de displasia broncopulmonar RESULTADOS: Foram analisados 1.825 recém-nascidos de muito baixo peso ao nascer. As médias de peso ao nascer e a idade gestacional foram de 1.085±279g e 29±3 semanas, respectivamente. A incidência de displasia broncopulmonar foi de 24,4%, e a sobrevida sem displasia broncopulmonar aumentou quanto maior foi a idade gestacional. Maior peso ao nascer, maior idade gestacional e sexo feminino estiveram associados a um menor risco de displasia broncopulmonar. Aumentaram o risco de displasia broncopulmonar: ventilação mecânica, necessidade de surfactante, escape aéreo, persistência do canal arterial, sepse tardia e enterocolite necrotizante. As crianças com displasia broncopulmonar requerem um maior tempo hospitalização (91±27 versus 51±19), de ventilação mecânica (19±20 versus 4±7) e de oxigenioterapia (72±30 versus 8±14). CONCLUSÕES: A incidência de displasia broncopulmonar foi de 24,4% em uma ampla população sul-americana e se relaciona com uma maior utilização de recursos. Os fatores de risco associados à displasia broncopulmonar encontrados nesse estudo foram: ventilação mecânica, necessidade de surfactante, escape aéreo, persistência do canal arterial, sepse tardia e enterocolite necrotizante. As informações contidas neste estudo podem ser úteis para o delineamento de estratégias perinatais de prevenção da morbidade.

OBJECTIVE: To determine the incidence of bronchopulmonary dysplasia, its risk factors and resource utilization in a large South American population of very low birth weight infants. METHODS: Data were prospectively collected from infants weighing 500 to 1,500 g born at 16 NEOCOSUR Network centers from 10/2000 through 12/2003. Multivariate relative risk and 95% confidence intervals were estimated by Poisson regression with robust error variance to find factors that affected the risk of bronchopulmonary dysplasia. RESULTS: 1,825 very low birth weight infant survivors were analyzed. Mean birth weight and gestational age were 1085+279 g and 29+3 weeks respectively. Bronchopulmonary dysplasia incidence averaged 24.4% and survival without bronchopulmonary dysplasia augmented with increasing gestational age. Higher birth weight and gestational age and a female gender all decreased the risk for bronchopulmonary dysplasia. Factors that independently increased that risk were surfactant requirement, mechanical ventilation, air leak, patent ductus arteriosus, late onset sepsis and necrotizing enterocolitis. Bronchopulmonary dysplasia infants had more days of hospitalization (91±27 vs. 51±19), on mechanical ventilation (19±20 vs. 4±7) and oxygen therapy (72±30 vs. 8±14) in comparison with non BPD infants. CONCLUSIONS: Bronchopulmonary dysplasia incidence was 24.4% in a large South American population and is related to greater resource utilization. Risk factors for bronchopulmonary dysplasia in this study were: surfactant requirement, mechanical ventilation, air leak, patent ductus arteriosus, late onset sepsis and necrotizing enterocolitis. These studies may provide information useful to the design of effective preventive perinatal strategies.

Neonates often develop severe bacterial infections, at this age there is a failure in the quantity and quality of the phagocytic system, often associated with a neutropenia. This is usually more severe in the premature contributing to the higher mortality seen in this group. Recent publications favour the use of GCSF for the prevention of nosocomial infections. This was a prospective study to evaluate the early use of GCSF in the prevention of hospital acquired infection in preterm neonates. 34 preterms were randomized to treatment with GCSF and 34 to the placebo group. In this double blind trial there was no reduction in infections in this group of patients inspite of achieving a significant neutrophilia. Conclusions: In this trial GCSF was not useful in the prevention of nosocomial infections in premature neonates

Resumen El recién nacido presenta con frecuencia infecciones bacterianas severas que pueden o no acompañarse de neutropenia, las que se ven favorecidas por una insuficiencia cualitativa y cuantitativa del sistema fagocítico neutrófilo en esta etapa de la vida. Lo anterior se acentúa aún más en el prematuro, lo que contribuye a altas tasas de morbimortalidad por infección. Publicaciones recientes sugieren la utilidad del factor estimulante de colonias granulocíticas (rH-GCF). El objetivo de nuestro estudio fue la evaluación prospectiva del uso precoz de rH-GCSF en prevención de sepsis nosocomial. Pacientes y Métodos: Se estudiaron 68 recién nacidos pretérmino de menos de 32 semanas de edad gestacional y peso inferior a 1 500 g, libres de infección clínica. 34 de ellos fueron asignados a tratamiento diario por un período de 15 días con rH-GCSF desde antes de las 72 horas de vida; la asignación se realizó en forma ciega y randomizada por tablas de números al azar. Resultados: la morbilidad infecciosa tanto sospechada como confirmada no mostró diferencias entre ambos grupos, a pesar de lograr una neutrofilia significativa. Conclusión: En este estudio, rH-GCF no demostró ser útil en la prevención de sepsis de origen intrahospitalario

Background: Anemia is common among very low birth weight newborns and requires frequent blood tranfusions. Erythropoietin was been reported to be useful in the prevention of this anemia. Aim: To asses the benefits of early (before the third week of life) Human recombinant Erythropoietin (r-EPO) administration to reduce the requirement of blood tranfusions in very low birth weight newborns. Patients and methods: sixty newborns under 1500g of birthweight were randomly assigned to recive r-EPO (n=29) or placebo (n=31) three times per week, during four weeks. Packed red cell volume and reticulocyte counts were measured weekly. Serum erythropoietin was measured prior to eigth dose. Transfusion requirements were recorded. Results: r-EPO reduced transfusions from 1.41 ± 1.1 to 0.69 ± 1 transfusions/newborns (p<0.001). At the fourth week of treatment, reticulocyte count was 14.8 ± 7 and 6.4 ± 4.9% in the active treatment group and placebo group respectively (p<0.001). Conclusions: r-EPO reduces the requrement of transfusions in low birth weight infants (Rev Méd Chile 2000; 128: 1313-17).