大脑中动脉血流指数诊断孕晚期不同孕周胎儿缺氧的意义

The Significance of Middle Cerebral Artery Blood Flow Indexes in the Diagnosis of Fetal Intrauterine Hypoxia at Different Gestational Weeks

目的:探讨胎儿大脑中动脉(MCA)血流指数诊断孕晚期不同孕周胎儿缺氧的临床应用价值。方法:选择2016年1月至2016年12月在我院行产前检查并于孕28~41^(+6)周住院分娩且经生后证实的无宫内缺氧新生儿1017例,宫内缺氧新生儿218例,均于产前应用彩色多普勒超声检测胎儿MCA血流动力学指数[阻力指数(RI)、搏动指数(PI)、收缩期峰值流速舒张期流速比值(S/D)],比较孕晚期不同孕周(孕28~31^(+6)周、孕32~36^(+6)周,孕37~41^(+6)周)MCA各项血流指数情况,并判断其诊断效能。结果:①孕晚期正常胎儿MCA血流指数随孕周的升高而降低,孕足月降低显著。②孕晚期胎儿发生缺氧时,MCA各项血流指数降低显著。以RI<0.6、PI<1.6、S/D<4.0为标准诊断孕28~31^(+6)周胎儿缺氧的约登指数为0.95,诊断孕32~36^(+6)周胎儿缺氧的约登指数为0.96,诊断孕37~41^(+6)周胎儿缺氧的约登指数为0.18。③对孕足月胎儿MCA作ROC曲线得出RI、PI、S/D的截断值分别为0.74、1.37、3.85,均高于正常均值。结论:胎儿MCA血流指数在诊断孕晚期不同孕周胎儿缺氧意义不同,对孕37~41^(+6)周孕足月胎儿不具诊断意义,应考虑孕周的影响以提高胎儿缺氧的诊断准确率。

Objective：To explore the clinical value of middle cerebral artery （MCA） blood flow indexes in diagnosing fetal intrauterine hypoxia in different gestational weeks of late pregnancy. Methods： From January 2016 to December 2016,1017 neonates without intrauterine hypoxia and 218 neonates with intrauterine hypoxia by postpartum were subjec- ted to a prenatal examination and hospital delivery at 28 -41^＋6 weeks in our hospital. The MCA hemodynamic indicators [ resistance index （RI）,pulsation index （PI）,the peak systolic velocity of diastolic velocity ratio （S/D） l of all the sub- jects were tested by color Doppler ultrasound in the prenatal stage. The MCA hemodynamic indicators were compared among different gestational weeks（28-31^＋6 weeks,32-36^＋6 weeks,37-41^＋6 weeks）in late pregnancy,and their diagnosis efficacy were analyzed. Results：①The blood flow parameters of MCA in late pregnancy decreased with the increase of gestational age,decreased significantly at full-term pregnancy. ②During the late pregnancy,the blood flow parameters of MCA decreased significantly when fetal hypoxia occurred. RI 〈0. 6, PI 〈 1.6,S/D 〈4. 0 as the standard for diagnosing fetal hypoxia,Youden index was 0. 95 at 28 -31^＋6 weeks,0. 96 at 32 -36^＋6 weeks,0. 18 at 37 -41^＋6 weeks,respectively. ③ROC of MCA in the full-term was obtained. The Cut-off values of RI ,PI and S/D were 0. 74,1.37 and 3, 85 respectively,whichwere higher than the normal mean values all of them. Conclusions. The significance of MCA is different in the diagnosis of intrauterine hypoxia at different gestational weeks,The MCA indexes have no diagnostic significance for intrauterine hypoxia in full-term pregnancy. The impact of gestational week should be considered in order to improve the diagnostic accuracy of fetal hypoxia.