PLACENTAL TRANSFUSION: EARLY VERSUS LATE CLAMPING OF THE UMBILICAL CORD

Abstract

IATROGENIC interruption of the placental circulation at birth has, in most cases become an automatic procedure with little or no regard for the physiologic alterations evoked or for their subsequent effect upon the fetus. The relative merits of "early" and "late" clamping of the umbilical cord have been the subject of controversy for many years. More recently it has been suggested that the time of cord clamping may be involved in the pathogenesis of idiopathic respiratory distress syndrome (IRDS). As of this writing, the controversy of "early" versus "late" clamping remains unsettled. Review of the pertinent literature indicates that this is due largely to failure to define uniformly "early" and "late," failure by many to consider the effects of onset of respiration, of gravity, of uterine contractions, and, in some instances, to conclusions not completely warranted by supporting data. In view of the potential significance of the issue and the current confusion surrounding it, critical re-examination appears to be in order. A major purpose of this review is to call attention to the areas of investigation needing further documentation. Effect on Blood Volume The blood volume of newly born infants has been studied by a number of investigators. In Table I are listed six studies in which the time of cord clamping was taken into account. In a study of 35 infants, DeMarsh, Windle, and Alt found a significant increase in blood volume when cord clamping was delayed until after separation of the placenta. In a similar study by Whipple, Sisson, and Lund these results were not confirmed.