Ventilation before Umbilical Cord Clamping improves the physiological transition at birth.

REVIEW ARTICLE PEDIATRICS published: 20 October 2014 doi: 10.3389/fped.2014.00113 Ventilation before umbilical cord clamping improves the physiological transition at birth Sasmira Bhatt 1,2 , Graeme R. Polglase 1,2 , Euan M. Wallace 1,2 , Arjan B. te Pas 3 and Stuart B. Hooper 1,2 * 1 The Ritchie Centre, MIMR-PHI Institute of Medical Research, Monash University, Melbourne, VIC, Australia Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia 3 Department of Pediatrics, Leiden University Medical Centre, Leiden, Netherlands 2 Edited by: Heber C. Nielsen, Tufts School of Medicine, USA Reviewed by: Drucilla Jane Roberts, Massachusetts General Hospital, USA Jonathan Michael Klein, University of Iowa, USA *Correspondence: Stuart B. Hooper , The Ritchie Centre, Monash Institute of Medical Research, 27-31 Wright Street, Clayton, VIC 3168, Australia e-mail: The transition from a fetus to a neonate at birth represents a critical phase in our life. Most infants make this transition without complications, but preterm infants usually require some form of assistance due to immature cardiopulmonary systems that predispose them to lifelong sequelae. As the incidence of preterm birth is increasing, there is now an urgent need for the development of management strategies that facilitate this transition, which will likely include improved strategies for the management of the maternal third stage of labor. For instance, recent studies on the physiological transition at birth have led to the discovery that establishing ventilation in the infant before the umbilical cord is clamped greatly stabilizes the cardiovascular transition at birth. While most benefits of delayed clamping previously have been attributed to an increase in placenta to infant blood transfusion, clearly there are other significant benefits for the infant, which are not well understood. Nevertheless, if ventilation can be established before cord clamping in a preterm infant, the large adverse changes in cardiac function that normally accompanies umbilical cord clamping can be avoided. As preterm infants have an immature cerebral vascular bed, large swings in cardiovascular function places them at high risk of cerebral vascular rupture and the associated increased risk of mortality and morbidity. In view of the impact that cord clamping has on the cardiovascular transition at birth, it is also time to re-examine some of the strategies used in the management of the third stage of labor. These include the appropriate timing of uterotonic administration in relation to delivery of the infant and placenta. As there is a lack of evidence on the effects these individual practices have on the infant, there is a necessity to improve our understanding of their impact in order to develop strategies that facilitate the transition to newborn life. Keywords: neonatal, preterm birth, transition, umbilical cord clamping, delayed cord clamping INTRODUCTION One of the first major interventions that an infant experiences following birth is umbilical cord clamping (UCC) and its separation from the placenta. This signifies a landmark period during which the newborn transforms into an independent entity. Much interest has recently focused on the appropriate timing of UCC, particularly on the risks and benefits of delaying cord clamping for a set period of time after birth. Debate on appropriate timing of UCC following birth has been ongoing for several decades (even centuries), yet the ideal time still remains unknown. As a result, although the potential benefits of delayed umbilical cord clamping (DCC) have been documented,‘early’ or ‘immediate’ umbilical cord clamping (ICC) is the most widely used procedure and is part of the active management of third stage of labor; i.e., the period extending from complete delivery of the infant to complete delivery of the placenta (1, 2). Although the reasons for this are unclear, a lack of understanding and awareness of the issues associated with UCC are thought to be a major underlying factor (3, 4). The benefits and risks associated with DCC have been primarily attributed to an increase in neonatal blood volume, secondary to placento-fetal transfusion. But this does not readily explain all www.frontiersin.org observations commonly associated with DCC, for example the lower risks of cerebral hemorrhage and necrotizing enterocolitis (5). These benefits appear more in line with improvements in cardiac function, which may or may not be associated with an increase in blood volume. Recent evidence suggests that DCC until after ventilation onset maintains ventricular preload and stabilizes cardiovascular function during the transition, which provide an alternative explanation for the lower risk of cerebral hemorrhage (5, 6). That study highlighted the need to consider DCC with respect to the physiological changes that occur within the infant during its transition after birth, although this area has received relatively little attention. This article is focused on the science underpinning the physiological changes at birth and how the timing of UCC may influence these changes. Recently, an excellent review on DCC has been published (5), which details much of the clinical data published on the risks and benefits of DCC and so will not be repeated here. HISTORY Delayed umbilical cord clamping is not a modern concept, as some primitive cultures reportedly wait until well after delivery of the October 2014 | Volume 2 | Article 113 | 1 Bhatt et al. placenta before cutting the umbilical cord. Indeed, Erasmus Darwin in 1801, suggested that, “Another thing very injurious to the child, is the tying and cutting of the navel string too soon; which should always be left till the child has not only repeatedly breathed but till all pulsation in the cord ceases. As otherwise the child is much weaker than it ought to be.” (7). Similarly, numerous other scholars, dating from the 19th century have provided similar observations and opinions about the timing of UCC at birth (8). However, these opinions were based on observational studies and not on scientific evidence. Nevertheless, it seemed natural to these scholars to leave the cord intact until after the child had taken its first breath. This raises the question as to why ICC currently predominates. While some have attributed this to maintaining “custom,” other reasons include reducing the risk of post-partum hemorrhage (PPH), reducing neonatal blood loss before physiological closure of the cord, easier identification of placental detachment, minimizing the risks of rhesus iso-immunization, and time constraints amidst a busy and chaotic delivery suite environment (9, 10). CURRENT GUIDELINES ON THE TIMING OF UMBILICAL CORD CLAMPING Guidelines on the timing of UCC vary considerably world wide, although ICC is the most commonly used practice. However, as DCC is not associated with an increased incidence of adverse maternal effects, (...truncated)