Timing of umbilical cord clamping in term and preterm deliveries and infant and maternal outcomes: A systematic review of randomized controlled trials

Abstract

Active management of the third stage of labor (comprising administration of a uterotonic agent, cord clamping and cutting, and controlled cord traction) has supplanted the ‘physiological’ (noninterventionist) approach [1]; as a consequence the umbilical cord is usually clamped soon after delivery of the baby. The observation that the cord can contain up to 20 mL of blood [2] raised the possibility of delaying clamping to allow placental transfusion to the baby. One of the major advantages could be to increase the circulating volume and hemoglobin level. The benefits of the former include less respiratory distress and reduced need for later transfusions [3,4]. Increasing the hemoglobin level and iron stores is attractive because anemia in early infancy is a frequent problem, especially in developing countries. However these potential benefits need to be balanced against possible harmful effects, for the mother (postpartum hemorrhage and its consequences) [1,5,6] and infant (delayed resuscitation, hypothermia, polycythemia, hyperbilirubinemia and risk of intraventricular hemorrhage). The issue is complicated by the fact that term babies, preterm babies and very premature babies could behave as different cohorts, making it difficult to develop an empiric guideline for timing of cord clamping across all gestations.