Ghirardello Stefano, Di Tommaso Mariarosaria, Fiocchi Stefano, Locatelli Anna, Perrone Barbara, Pratesi Simone, Saracco Paola
Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.
Health Sciences Department, University of Firenze, Careggi University Hospital, Florence, Italy.
Front Pediatr. 2018 Dec 3;6:372. doi: 10.3389/fped.2018.00372. eCollection 2018.
At delivery, if the cord is not clamped, blood continues to pass from the placenta to the newborn during the first minutes of life, allowing the transfer of 25-35 ml/kg of placental blood to the newborn, depending on gestational age, the timing of cord clamping, the position of the infant at birth, the onset of respiration, and administration of uterotonics to the mother. However, deriving benefits from delayed cord clamping (DCC) are not merely related to placental-to-fetal blood transfusion; establishing spontaneous ventilation before cutting the cord improves venous return to the right heart and pulmonary blood flow, protecting the newborn from the transient low cardiac output, and systemic arterial pressure fluctuations. Recent meta-analyses showed that delayed cord clamping reduces mortality and red blood cell transfusions in preterm newborns and increases iron stores in term newborns. Various authors suggested umbilical cord milking (UCM) as a safe alternative when delayed cord clamping is not feasible. Many scientific societies recommend waiting 30-60 s before clamping the cord for both term and preterm newborns not requiring resuscitation. To improve the uptake of placental transfusion strategies, in 2016 an Italian Task Force for the Management of Umbilical Cord Clamping drafted national recommendations for the management of cord clamping in term and preterm deliveries. The task force performed a detailed review of the literature using the GRADE methodological approach. The document analyzed all clinical scenarios that operators could deal with in the delivery room, including cord blood gas analysis during delayed cord clamping and time to cord clamping in the case of umbilical cord blood banking. The panel intended to promote a more physiological and individualized approach to cord clamping, specifically for the most preterm newborn. A feasible option to implement delayed cord clamping in very preterm deliveries is to move the neonatologist to the mother's bedside to assess the newborn's clinical condition at birth. This option could safely guarantee the first steps of stabilization before clamping the cord and allow DCC in the first 30 s of life, without delaying resuscitation. Contra-indications to placental transfusion strategies are clinical situations that may endanger mother 's health and those that may delay immediate newborn's resuscitation when required.
分娩时，如果不夹紧脐带，在出生后的头几分钟内，血液会继续从胎盘流向新生儿，根据胎龄、脐带夹紧时间、婴儿出生时的体位、呼吸开始时间以及给母亲使用宫缩剂的情况，可使25 - 35毫升/千克的胎盘血转移到新生儿体内。然而，延迟脐带夹紧（DCC）带来的益处不仅仅与胎盘向胎儿的输血有关；在剪断脐带前建立自主呼吸可改善右心静脉回流和肺血流量，保护新生儿免受短暂的心输出量低和全身动脉压波动的影响。近期的荟萃分析表明，延迟脐带夹紧可降低早产儿的死亡率和红细胞输注率，并增加足月儿的铁储备。当延迟脐带夹紧不可行时，许多作者建议采用脐带挤奶法（UCM）作为一种安全的替代方法。许多科学协会建议，对于不需要复苏的足月儿和早产儿，在夹紧脐带前等待30 - 60秒。为了提高胎盘输血策略的采用率，2016年，一个意大利脐带夹紧管理特别工作组起草了关于足月和早产分娩中脐带夹紧管理的国家建议。该特别工作组使用GRADE方法对文献进行了详细的综述。该文件分析了操作人员在产房可能遇到的所有临床情况，包括延迟脐带夹紧期间的脐血气分析以及脐带血库保存情况下的脐带夹紧时间。该小组旨在推广一种更符合生理和个体化的脐带夹紧方法，特别是针对极早产儿。在极早产分娩中实施延迟脐带夹紧的一个可行选择是将新生儿科医生移至母亲床边，以评估新生儿出生时的临床状况。这一选择可以在夹紧脐带前安全地保证新生儿稳定的第一步，并允许在出生后的头30秒内进行延迟脐带夹紧，而不会延迟复苏。胎盘输血策略的禁忌症是可能危及母亲健康的临床情况，以及在需要时可能延迟新生儿立即复苏的情况。
