中孕筛查期胎儿循环血流动力学参数及与胎儿生长发育的相关性

Correlation between Fetal Circulation and Growth in the Second Trimester

目的研究中孕筛查期正常胎儿大脑中动脉（middle cerebral artery，MCA）、脐动脉（umbilical artery，UmA）及孕妇子宫动脉（uterineartery，UtA）血流动力学参数的关系，并探讨各项参数与胎儿生长发育的相关性。方法2011年6月至2012年7月于本院超声医学科就诊的常规中孕筛查期（20—24“周）孕妇206名，测量胎儿常规物理测量指标如双顶径、头围、腹围及股骨长；测量MCA、UmA及UtA的血流动力学参数，包括峰值流速（peak flow velocity，PSV）、阻力指数（resistance index，RI）、搏动指数（pulsatility index，PI），计算大脑胎盘搏动指数比值（CPR=MCA—PI／UmA-PI）和阻力指数比值（CRR=MCA．R／／UmA—RI）。结果孕20～24＋6周胎儿MCA—PSV范围为13．63—37．96cm／s，随孕周增加而呈递增趋势；而MCA—RI、MCA—PI、UmA—RI、UmA。PI、UtA．RI、UtA-PI及CPR、CRR随孕周变化不明显。MCA-RI与UmA—RI（r=0．51，P〈0．01）、MCA-PI与UmA-PI呈显著相关性（r=0．65，P〈0．01），而UtA—R1、UtA—PI与MCA和UmA的相应指数均无明显相关性。MCA—PSV（cm／s）和孕周（GA，周）呈线性相关关系：MCA—PSV=-0．17＋1．02×GA（r=0．67，P〈0．01）。MCA．PSV与双顶径、头围具有相关性（r=0．29，P〈0．01；r=0．32，P〈0．01）。结论中孕筛查期胎儿MCA的RI和PT与UmA相应指数密切相关，而与UtA血流动力学参数的相关性不大；MCA—PSV与孕周关系密切，并受脑部发育的影响。

Objective To explore the relationship among the hemodynamic parameters of middle cerebral artery （MCA）, umbilical artery （UmA）, and uterine artery （UtA） and fetal growth in the second trimester. Methods From June 2011 to July 2012, a total of 206 normal pregnant women with a gestation age of 20 -24＋6 weeks were examined by color Doppler ultrasound after routine screening scanning. The anatomic parameters including biparietal diameter （ BPD）, head circumference （ HC）, abdomen circumference, and femur length were recorded. Also, the hemodynamic parameters including peak flow velocity （PSV） of MCA, and pulsatility index （PI） and resistance index （RI） of MCA, UmA and UtA were measured. The cerebral placenta ratios （CPR = MCA-PI/UmA-PI; CRR = MCA-RI/UmA-RI） were calculated based on the measurements. Results The MCA- PSV （ranged from 13.63 -37.96 cm/s） indicated a mild elevation trend during the gestation; however, the other parameters including RI, PI of MCA, UmA, UtA and CPR, CRR remained stable during this period. The MCA-RI and MCA-PI were significantly correlated with UmA-RI and UmA-PI, respectively （r = 0. 51, P 〈 0. 01 ;r =0. 65, P 〈0. 01 ）. However, there was no correlation within the corresponding indexes between UtA and MCA or UmA. The MCA-PSV （cm/s） showed a significantly linear relationship with the gestational age （GA, week） ： MCA-PSV = -0. 17 ＋ 1.02 ~ GA （r =0. 67, P 〈0. 01 ）. The MCA-PSV was significantly correlated with BPD and HC （r=0.29, P〈0.01; r=0.32, P〈0.01）. Conclusions The RI and PI of MCA are closely correlated with those of UmA, but show no such correlation with those of UtA. The PSV in fetal brain is closely associated with the gestational week and affected by brain development.