[Early or late umbilical cord clamping? A systematic review of the literature].
BACKGROUND
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.


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.
Lainez Villabona
B
B
Becaria del Ministerio y Consumo, Instituto de Salud Carlos III, Fondo de Investigación Sanitaria, Servicio de Obstetricia, Hospital General de Vic, Barcelona, España. blancala15@hotmail.com
Bergel Ayllon
E
E
Cafferata Thompson
M L
ML
Belizán Chiesa
J M
JM
D003250:Constriction; D036861:Delivery, Obstetric; D006801:Humans; D007231:Infant, Newborn; D014470:Umbilical Cord