胎儿动脉指数与脐带绕颈压迹深度的相关性

Correlation between PI of fetal MCA and UA and the depth of fetal impression of umbilical cord around the neck

目的分析胎儿大脑中动脉(MCA)和脐动脉(UA)的搏动指数(PI)、阻力指数(RI)、收缩期最大速度/舒张期最小速度(S/D)与脐带绕颈压迹深度的相关性。方法选取2017年3年至2018年3月在绍兴市妇幼保健院就诊的200例孕晚期脐带绕颈胎儿,根据绕颈情况的不同将其分为:绕颈一周者为A组(163例),绕颈超过一周者为B组(37例),另选取同期50例正常胎儿为对照组。通过多普勒超声对各组胎儿的MCA和UA各血流参数进行检测,并分析胎儿MCA和UA各血流参数与脐带绕颈压迹深度的相关性,比较各组胎心的异常率、第二产程时间及分娩方式等差异。结果 A组压迹深度≥0.80cm的胎儿和B组胎儿MCA的PI、RI、S/D均显著高于对照组(F=4.95~5.32,P<0.05),而各组胎儿UA的PI、RI、S/D比较差异均无统计学意义(均P>0.05)。经Pearson相关性分析结果显示,A组压迹深度与MCA的PI、RI、S/D均存在正相关关系(r值分别为0.38、0.39、0.41,均P<0.05),而与UA的PI、RI、S/D均无显著相关关系(r值分别为0.10、0.07、0.12,均P>0.05);B组压迹深度与MCA的PI、RI、S/D均存在正相关关系(r值分别为0.55、0.70、0.72,均P<0.01),而与UA的PI、RI、S/D均无显著相关关系(r值分别为0.15、0.11、0.05,均P>0.05)。A组压迹深度≥0.80cm者胎心异常率较对照组显著升高(χ^2=13.25,P<0.05)。A组压迹深度≥0.80cm者第二产程时间较对照组明显延长(t=14.02,P<0.05)。A组、B组剖宫产率均较对照组明显增高(χ^2值分别为8.14、36.59,均P<0.05)。结论孕晚期胎儿脐带绕颈压迹深度与MCA的PI、RI、S/D密切相关,而与UA的PI、RI、S/D均无显著相关性,MCA各血流参数较UA更敏感,且绕颈一周压迹深度≥0.80cm者胎心异常率明显升高,第二产程时间延长,可能会导致胎儿宫内缺氧。

Objective To analyze the correlation between the pulsatility index(PI) of fetal middle cerebral artery(MCA) and umbilical artery(UA) and the depth of fetal impression of umbilical cord around the neck.Methods 200 fetuses with umbilical cord around the neck in late pregnancy admitted during the period from March 2013 to March 2018 in our hospital were selected.According to the different circumstance of umbilical rounding the neck,they were divided into group A(163 cases) that had it for one week,group B(37 cases) that had it for more than one week,and 50 normal fetuses were selected as the control group at the same time.The blood flow parameters of fetal MCA and UA were measured by Doppler ultrasound,and the correlation between the blood flow parameters of fetal MCA and UA and the depth of umbilical cord around neck were analyzed.The rate of abnormal fetal heart rate,the second stage of labor time,and delivery mode were compared.Results the PI,RI and S/D of MCA in group A fetuses whose depth of impression of umbilical cord around the neck ≥0.80 cm and group B were significantly higher than those in the control group(F=4.95-5.32,P<0.05),but there was no significant difference in PI,RI and S/D of UA between the two groups(P>0.05).Pearson correlation analysis showed that the indentation depth of group A was positively correlated with PI,RI and S/D of MCA(r=0.38,0.39,0.41,respectively,P<0.05 for all),but not with PI,RI and S/D of UA(r=0.10,0.07,0.12,respectively,P>0.05 for all),while the indentation depth of group B was positively correlated with PI,RI and S/D of MCA(r=0.55,0.70,0.72,respectively,P<0.01 for all),but there was no significant correlation with PI,RI and S/D of UA(r=0.15,0.11 and 0.05,respectively,P>0.05 for all).The abnormal rate of fetal heart rate in group A was significantly higher than that in the control group(χ^2=13.25,P<0.05).The second stage of labor in group A was longer than that in the control group(t=14.02,P<0.05).The rates of cesarean section in group A and B were significantly higher than that in the control group(χ^2=8.14,36.59,respectively,P<0.05).Conclusion The depth of fetal impression around neck of umbilical cord in late pregnancy is closely related to PI,RI and S/D of MCA,but not to PI,RI and S/D of UA,suggesting that the blood flow parameters of MCA are more sensitive than UA,and the abnormal rate of fetal heart is significantly increased in those with the depth of impression around neck being more than 0.80 cm.The prolongation of the second stage of labor may lead to intrauterine hypoxia.