目的： 建立低危人群妊娠11~40周子宫动脉平均搏动指数（mean pulsatility index，mPI）的正常参考值范围，并进行前瞻性验证。方法： 收集2019年01月至2023年07月于我院建卡并于11~40周行超声检查，测量两侧子宫动脉超声参数搏动指数（pulsatility index，PI）及舒张早期是否有切迹，随访至妊娠结局，并收集孕妇基本临床资料和胎儿出生信息。结果： 本研究共纳入1 365例正常妊娠结局的低危人群，另纳入同期104例妊娠结局不良者用于验证该参考范围，包括妊娠高血压（41例）及胎儿生长受限（23例）等。随着其孕周增加，mPI呈逐渐下降的趋势,孕20周前呈快速下降（孕11周、20周时mPI第95百分位分别为2.35、1.54），随后下降缓慢，至孕32周后mPI趋于稳定（孕32周、39周时mPI第95百分位数分别为0.91、0.87）。随着孕周的增加，两侧子宫动脉舒张早期切迹的检出率呈逐渐下降的趋势，孕11~15周检出率为69.20%，孕21~25周检出率为27.01%，之后趋于稳定，孕36~40周降至6.31%。受试者操作特征曲线分析结果显示，相应孕周mPI≥第95百分位预测妊娠期高血压疾病的灵敏度为30.11%，特异度为93.21%；预测胎儿生长受限的灵敏度为61.9%,特异度为92.85%。结论： 建立低危人群妊娠11~40周子宫动脉mPI的正常参考值范围，用于前瞻性排除妊娠高血压、胎儿生长受限具有一定价值。

Objective: To establish and verify the normal reference range of uterine artery mean pulsatility index (mPI) between 11-40 weeks of pregnancy in low-risk population. Methods: Pregnant women registered in our hospital from January 2019 to July 2023 and underwent ultrasound examination at 11 to 40 weeks were enrolled. By Ultrasound diagnosis, the pulsatility index (PI) of bilateral uterine arteries were measured, and whether there was a notch in the early diastolic period was checked. Following up the pregnancy, basic clinical data and fetal birth information were collected. Results: A total of 1365 low-risk people with normal pregnancy outcomes were included. The 104 cases of adverse pregnancy outcomes were wed to verify the refernce range, including pregnancy included hypertension (n=41) and fetalgrowth restriction (n=23). With the increase of gestation age, mPI showed a gradual downward trend. There was a rapid decline before 20 weeks of gestation (mPI 95th percentile at 11 weeks and 20 weeks of gestation were 2.35 and 1.54, respectively), then declined slowly, and mPI stabilized after 32 weeks of gestation (95th percentile mPI at 32 weeks and 39 weeks of gestation were 0.91 and 0.87, respectively). With the increase of gestation age, the detection rate of early diastolic notch in bilateral uterine arteries decreased gradually. The detection rate was 69.20% at 11-15 weeks of gestation, 27.01% at 21-25 weeks of gestation, then stabilized and decreased to 6.31% at 36-40 weeks of gestation. The results of receiver operating characteristic (ROC) curve analysis showed that the sensitivity and specificity of mPI ≥95^th precentile in predicting hypertensive disorder complicating pregnancy were 30.11% and 93.21%, respectively; The sensitivity and specificity in predicting fetal growth restriction were 61.9% and 92.85%, respectively. Conclusions: Establishing the reference range of uterine artery mPI at 11-40 weeks of pregnancy in low-risk population may be used for prospective exclusion of gestational hypertension and fetal growth restriction.