[Variations in serum ferritin and erythrocyte index in the first eight weeks of life in term newborn infants]. / Variaciones en la ferritina sérica e índices eritrocitarios en las primeras ocho semanas de vida en recién nacidos a término.

OBJECTIVE: To describe changes in erythrocyte index during the first 8 weeks of life in neonates in relation to their iron store. MATERIAL AND METHODS: We performed a longitudinal study of a group of healthy term newborn infants, in whom we evaluated erythrocyte index and serum ferritin (SF) values at birth and at weeks 4 and 8 of age. Depending on the comparison made in SF values between birth and 2 months, the infants were divided into two groups: group I (without variation in SF) and group II (with a decrease in SF). RESULTS: A total of 110 neonates were included, with 46 neonates in group I and 64 in group II. No differences in demographic or hematologic data were found, including neonates with anemia or a decrease in hemoglobin values (5.2 vs. 5.5 g/dL). SF decreased to lower values in group II than in group I (215 vs. 194 microg/L, p < 0.001), with a greater number of neonates with low iron stores at 2 months of age (0.15 vs. 0.37, p < 0.01; RR 2.464, 95 % CI: 1.162-5.227). CONCLUSIONS: In healthy term newborn infants, erythrocyte index at birth showed no relation with iron store. SF values at 2 months of age depended on SF concentrations at birth. Decreased hemoglobin and SF values are part of physiological adaptation in the first few months of life.

Variaciones en la ferritina sérica e índices eritrocitarios en las primeras ocho semanas de vida en recién nacidos a término / Variations in serum ferritin and erythrocyte index in the first eight weeks of life in term newborn infants

Objetivo: Describir los cambios en los índices eritrocitarios en las primeras 8 semanas de vida del recién nacido en relación a la reserva corporal de hierro. Material y métodos: Mediante un estudio longitudinal se incluyeron recién nacidos a término sanos, evaluando los índices eritrocitarios y la ferritina sérica al nacer, a las 4 y a las 8 semanas de edad. De acuerdo a la comparación de la ferritina entre el nacimiento y los 2 meses, se dividieron en grupo I (sin variación en la ferritina) y el grupo II (disminución de la ferritina). Resultados: Se incluyeron 110 casos, con 46 y 64 recién nacidos para cada grupo. No se documentaron diferencias en las variables demográficas o en los índices eritrocitarios incluyendo casos de anemia o descenso de los valores de hemoglobina (5,2 g/dl frente a 5,5 g/dl). La ferritina sérica disminuyó a valores más bajos en el grupo II (215 ìg/l frente a 194 ìg/l; p < 0,001), con mayor proporción de casos con reserva baja de hierro a los 2 meses de edad (0,15 frente a 0,37; p < 0,01; riesgo relativo, 2,464; IC 95 %: 1,162-5,227). Conclusiones: En recién nacidos a término sanos, los valores de los índices eritrocitarios al nacer no muestran relación alguna con la reserva de hierro. La ferritina sérica a los 2 meses de edad depende de sus concentraciones al nacimiento. Estos cambios forman parte de una adaptación fisiológica en los primeros meses de vida

Objective: To describe changes in erythrocyte index during the first 8 weeks of life in neonates in relation to their iron store. Material and methods: We performed a longitudinal study of a group of healthy term newborn infants, in whom we evaluated erythrocyte index and serum ferritin (SF) values at birth and at weeks 4 and 8 of age. Depending on the comparison made in SF values between birth and 2 months, the infants were divided into two groups: group I (without variation in SF) and group II (with a decrease in SF). Results: A total of 110 neonates were included, with 46 neonates in group I and 64 in group II. No differences in demographic or hematologic data were found, including neonates with anemia or a decrease in hemoglobin values (5.2 vs. 5.5 g/dL). SF decreased to lower values in group II than in group I (215 vs. 194 ìg/L, p < 0.001), with a greater number of neonates with low iron stores at 2 months of age (0.15 vs. 0.37, p < 0.01;RR 2.464, 95 % CI: 1.162-5.227). Conclusions: In healthy term newborn infants, erythrocyte index at birth showed no relation with iron store. SF values at 2 months of age depended on SF concentrations at birth. Decreased hemoglobin and SF values are part of physiological adaptation in the first few months of life