Kidz First, Middlemore Hospital, Auckland, New Zealand.
Arch Dis Child Fetal Neonatal Ed. 2012 Nov;97(6):F484-6. doi: 10.1136/adc.2010.199703. Epub 2011 May 17.
To determine if timing of cord clamping affects blood flow in the upper body, as measured by flow in the superior vena cava (SVC).
Observational study.
Neonatal Unit, Middlemore Hospital, Auckland, New Zealand.
30 preterm infants <30 weeks' gestational age.
Cord clamping was immediate in 17 infants and delayed by 30-45 s in 13.
Infants in the two groups did not differ significantly in terms of gestational age, gender or use of antenatal steroids. Median flow in the SVC in the first 24 h was significantly higher in the group with delayed clamping (median 91 ml/kg/min; IQR 81-101) compared with 52 ml/kg/min (IQR 42-100) in the immediate clamping group (p=0.028). Fewer infants in the delayed group had low flow (1 compared with 9; p=0.017). All three infants with intraventricular haemorrhage (IVH) (of any grade) had low flow.
Blood flow in the SVC was higher in infants where delayed cord clamping was performed. The relationship of IVH, low flow and timing of cord clamping requires further study.
通过测量上腔静脉（SVC）的血流量来确定脐带夹闭的时机是否会影响上半身的血流。
观察性研究。
新西兰奥克兰米德尔莫尔医院新生儿病房。
30 名胎龄<30 周的早产儿。
17 名婴儿立即夹闭脐带，13 名婴儿延迟 30-45 秒夹闭脐带。
两组婴儿在胎龄、性别或产前使用类固醇方面无显著差异。延迟夹闭组婴儿在出生后 24 小时内 SVC 的中位血流量明显高于立即夹闭组（中位数 91ml/kg/min；IQR 81-101）（p=0.028），立即夹闭组为 52ml/kg/min（IQR 42-100）。延迟夹闭组中低流量（<40ml/kg/min）的婴儿较少（1 例与 9 例；p=0.017）。所有 3 例伴有脑室内出血（IVH）（任何程度）的婴儿均有低流量。
延迟夹闭脐带可增加 SVC 的血流量。IVH、低流量和脐带夹闭时机之间的关系需要进一步研究。
