[Early or late umbilical cord clamping? A systematic review of the literature]. / 'Pinzamiento precoz o tardío del cordón umbilical? Una revisión sistemática de la literatura médica.

INTRODUCTION: There is wide variability in clinical practice in the moment of clamping the umbilical cord. Opinions in the medical community differ on the harm and/or benefits, both for the mother and for the newborn, of early versus late cord clamping. Currently, the debate among those who defend and/or criticize one or other of these practices continues. The aim of this study was to evaluate the effects of early versus late clamping of the umbilical cord in full-term newborns on maternal and neonatal outcomes. MATERIAL AND METHODS: A literature search of randomized clinical trials was carried out in the Cochrane Library, MEDLINE and Lilacs. It was completed with a hand search of references in relevant articles. All randomized controlled clinical trials of good methodological quality that compared early versus late cord clamping in term newborns were selected. RESULTS: Of seven identified studies, four had the required characteristics for inclusion in this systematic review. Comparison of early versus late clamping in these studies revealed that late clamping could diminish the prevalence of children with low iron reserves at 3 months of age by 50%, but this result comes from a study that lost more than 40% of the patients during follow-up. The results concerning anemia at 3 months of age showed statistical heterogeneity since the two studies that analyzed this outcome had opposite results. For other outcomes such as birth weight, Apgar < 5, and tachypnea the studies were too small for significant differences to be detected. CONCLUSIONS: This review shows that there is no clear evidence for defending any of the modalities of cord clamping in full-term newborns. Further research is needed to identify the best moment for cord clamping.

¿Pinzamiento precoz o tardío del cordón umbilical? Una revisión sistemática de la literatura médica / Early or late umbilical cord clamping? A systematic review of the literature

Introducción. Existe una gran variabilidad en la práctica clínica en cuanto al momento de pinzar el cordón umbilical. La comunidad médica manifiesta diferentes opiniones acerca de los daños y/o beneficios, tanto para la madre como para el recién nacido, del pinzamiento precoz frente al tardío. Actualmente continúa el debate entre los que defienden y/o critican cualquiera de estas prácticas. El objetivo de este estudio es evaluar los efectos maternos y neonatales del pinzamiento precoz del cordón umbilical comparado con el pinzamiento tardío en recién nacidos a término. Material y métodos. Se realizó la búsqueda bibliográfica en PubMed, la biblioteca Cochrane (Registro de estudios controlados), Lilacs y búsqueda manual de citas bibliográficas en artículos relevantes. Se seleccionaron todas las investigaciones clínicas controladas aleatorizadas de buena calidad metodológica que compararan el pinzamiento precoz del cordón con el pinzamiento tardío en el recién nacido a término. Resultados. De siete estudios identificados cuatro de ellos reunieron las características para ser seleccionados para su inclusión. Al comparar el pinzamiento precoz comparado con el tardío la revisión de los estudios mostró que el pinzamiento tardío podría disminuir la prevalencia de niños con bajas reservas de hierro a los 3 meses en el 50 %; sin embargo, estos resultados provinieron de un estudio que perdió más del 40 % de los pacientes durante el seguimiento. Para el resultado de anemia a los 3 meses, hubo heterogeneidad estadística en los resultados ya que los dos estudios mostraron efectos opuestos. Para los resultados de peso al nacimiento, Apgar inferior a 5 y taquipnea los estudios fueron muy pequeños para poder detectar diferencias significativas. Conclusiones. Esta revisión muestra que no existe clara evidencia para propiciar ninguna de las dos maneras de pinzamiento del cordón. Se requieren investigaciones que permitan establecer directrices sobre la conducta que se debe seguir

Introduction. There is wide variability in clinical practice in the moment of clamping the umbilical cord. Opinions in the medical community differ on the harm and/or benefits, both for the mother and for the newborn, of early versus late cord clamping. Currently, the debate among those who defend and/or criticize one or other of these practices continues. The aim of this study was to evaluate the effects of early versus late clamping of the umbilical cord in full-term newborns on maternal and neonatal outcomes. Material and methods. A literature search of randomized clinical trials was carried out in the Cochrane Library, MEDLINE and Lilacs. It was completed with a hand search of references in relevant articles. All randomized controlled clinical trials of good methodological quality that compared early versus late cord clamping in term newborns were selected. Results. Of seven identified studies, four had the required characteristics for inclusion in this systematic review. Comparison of early versus late clamping in these studies revealed that late clamping could diminish the prevalence of children with low iron reserves at 3 months of age by 50 %, but this result comes from a study that lost more than 40 % of the patients during follow-up. The results concerning anemia at 3 months of age showed statistical heterogeneity since the two studies that analyzed this outcome had opposite results. For other outcomes such as birth weight, Apgar < 5, and tachypnea the studies were too small for significant differences to be detected. Conclusions. This review shows that there is no clear evidence for defending any of the modalities of cord clamping in full-term newborns. Further research is needed to identify the best moment for cord clamping