Jahazi A, Kordi M, Mirbehbahani N B, Mazloom S R
Midwifery Department, Gorgan Branch, Islamic Azad University, Golestan, Iran.
J Perinatol. 2008 Aug;28(8):523-5. doi: 10.1038/jp.2008.55. Epub 2008 Jul 3.
To compare the effect of early and late cord clamping (LCC) on neonatal hematocrit at 2 and 18 h of life.
In this double-blind randomized trial, 64 healthy full-term vaginally born neonates were randomly allocated to either early (30 s) or late (3 min) umbilical cord clamping. During the interval between delivery and cord clamping, the attendant held the neonate supine at the level of the introitus. Neonatal venous hematocrit was measured at 2 and 18 h of life.
Neonatal hematocrit at 2 h of life (61+/-4.9 vs 61.6+/-4.5%) and 18 h of life (56.9+/-4.1 vs 56.2+/-3.9%) was not significantly different between the two groups. This was also true for neonatal polycythemia (20 vs 23.5%). In the LCC group, placental residual blood volume (PRBV) was 39.5% lower and estimated neonatal blood volume (ENBV) was 7.1% higher than that in the early cord clamping (ECC) group (P<0.001).
Late cord clamping does not lead to a significant difference in the hematocrit level of the neonate or neonatal polycythemia, but is associated with a significant increase in ENBV and a significant decrease in PRBV. Further trials should examine the effect of delaying cord clamping for a longer period of time or changing the position that the neonate is held in to determine whether these variations result in more clinically significant results.
比较早断脐与晚断脐对出生2小时和18小时新生儿血细胞比容的影响。
在这项双盲随机试验中,64名健康的足月阴道分娩新生儿被随机分配至早断脐组(30秒)或晚断脐组(3分钟)。在分娩至断脐的间隔期,护理人员让新生儿仰卧于阴道口水平。于出生2小时和18小时测量新生儿静脉血细胞比容。
两组在出生2小时(61±4.9%对61.6±4.5%)和18小时(56.9±4.1%对56.2±3.9%)时的新生儿血细胞比容无显著差异。新生儿红细胞增多症情况(20%对23.5%)亦是如此。与早断脐组相比,晚断脐组的胎盘残余血量(PRBV)降低了39.5%,估计新生儿血容量(ENBV)增加了7.1%(P<0.001)。
晚断脐不会导致新生儿血细胞比容水平或新生儿红细胞增多症出现显著差异,但与ENBV显著增加及PRBV显著减少有关。进一步的试验应研究延长断脐延迟时间或改变新生儿体位的影响,以确定这些变化是否会产生更具临床意义的结果。