Department of Paediatric Pathology, Addenbrookes Hospital, Cambridge, UK.
Virchows Arch. 2014 Jan;464(1):105-12. doi: 10.1007/s00428-013-1513-2. Epub 2013 Nov 21.
This study was conducted to determine the frequency of pre-defined clinical outcomes in relation to umbilical cord coiling indices >90th percentile and <10th percentile in an unselected population of >1,000 women with a singleton pregnancy resulting in livebirth delivering at or near term and to report these findings in the context of a systematic review. Placentas of consecutive deliveries from an unselected low-risk population with >15 cm attached umbilical cords were included in the study. Clinical outcomes included interventional delivery, birthweight <10th percentile, Apgar score <7 at 1 min, neonatal acidosis (pH<7.2) and admission to neonatal special care. Standard MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines were observed for the systematic review. Umbilical coiling index was determined for 1,082 placentas. Mean maternal age was 30.7 years (standard deviation [SD] =5.7) and 519 women (48 %) were primiparous. Mean cord length was 43 cm (SD=13) and mean cord coiling index 0.20 (SD=0.09). A total of 866 cords were normally coiled, and 108 cases were hypercoiled (>90th centile) and 108 cases were undercoiled (<10th percentile). There were no differences between cases of overcoiled, normally coiled or undercoiled cords for any clinical outcome studied. The systematic review yielded a small number of clinical studies which were too statistically and clinically heterogenous to permit meta-analysis. There is insufficient evidence either from this unselected cohort study or from a systematic review to support the previous suggestion that cord coiling index >90th centile or <10th centile is associated with adverse clinical outcome in an unselected population. Previous studies that draw a link between abnormal cord coiling and clinical outcome are generally too small and/or selective to allow meaningful conclusions or applicability to low-risk populations.
这项研究旨在确定在一个超过 1000 名单胎妊娠、足月或接近足月分娩、活产的未选择人群中，脐带缠绕指数>第 90 百分位数和<第 10 百分位数与预定义临床结局的频率，并在系统评价的背景下报告这些发现。研究纳入了一个未选择的低危人群中连续分娩的胎盘，这些胎盘的脐带附着长度超过 15 厘米。临床结局包括干预性分娩、出生体重<第 10 百分位数、1 分钟时 Apgar 评分<7、新生儿酸中毒（pH<7.2）和新生儿重症监护室收治。系统评价遵循标准 MOOSE（观察性研究的荟萃分析）指南。对 1082 个胎盘进行了脐带缠绕指数的测定。产妇的平均年龄为 30.7 岁（标准差[SD]=5.7），519 名妇女（48%）为初产妇。平均脐带长度为 43 厘米（SD=13），平均脐带缠绕指数为 0.20（SD=0.09）。共有 866 根脐带正常缠绕，108 例脐带缠绕过度（>第 90 百分位数），108 例脐带缠绕不足（<第 10 百分位数）。在研究的任何临床结局中，过度缠绕、正常缠绕或不足缠绕的脐带之间没有差异。系统评价得出的少数临床研究在统计学和临床方面差异太大，无法进行荟萃分析。无论是从这个未选择的队列研究还是从系统评价中，都没有足够的证据支持脐带缠绕指数>第 90 百分位数或<第 10 百分位数与未选择人群中不良临床结局相关的先前建议。以前那些将异常脐带缠绕与临床结局联系起来的研究通常规模较小且/或选择偏倚较大，无法得出有意义的结论或适用于低危人群。
