Horgan R, Sinkovskaya E, Saade G, Kalafat E, Heeze A, Abuhamad A
Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Macon & Joan Brock Virginia Health Sciences, Old Dominion University, Norfolk, VA, USA.
Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
Ultrasound Obstet Gynecol. 2025 Jul 29. doi: 10.1002/uog.29308.
To use superb microvascular imaging (SMI) to longitudinally evaluate blood flow in intravillous arterioles (IVA) in pregnancy, and to develop reference ranges for IVA pulsatility index (PI) and peak systolic velocity (PSV) from 12 to 38 weeks' gestation.
The data for this study were obtained from the National Institutes of Health-funded Human Placenta Project. Eligible for inclusion were women aged 18-35 years, with a body mass index of < 30 kg/m, without comorbidities, with a singleton pregnancy conceived spontaneously and a gestational age of ≤ 13 + 6 weeks. Exclusion criteria were maternal or neonatal complications, fetal or umbilical cord anomalies, abnormal placental implantation and delivery < 37 weeks. Each participant underwent eight ultrasound examinations during pregnancy. Using SMI technology, the total number of IVA identified was recorded in a sagittal placental section at the level of cord insertion. The PI and PSV were measured in a total of six IVA (two in the central portion of the placenta, two peripherally towards the uterine fundal portion and two peripherally towards the lower uterine segment). Umbilical artery (UA)-PI was also obtained. Multilevel regression models were used to create reference ranges for IVA-PI and IVA-PSV at 12-38 weeks' gestation.
A total of 90 women fulfilled the study criteria. IVA-PI decreased throughout pregnancy from a mean ± SD of 1.04 ± 0.23 in the first trimester (at 12-13 weeks) to 0.75 ± 0.10 in the late third trimester (at 36-37 weeks). Mean IVA-PSV increased from 5.97 ± 1.47 cm/s at 12-13 weeks to 12.65 ± 4.19 cm/s at 28-29 weeks, and then plateaued throughout the third trimester, to 13.09 ± 4.64 cm/s at 36-37 weeks. UA-PI decreased progressively throughout pregnancy, from 1.49 ± 0.22 at 16-17 weeks to 0.89 ± 0.18 at 36-37 weeks. Reference ranges for IVA-PI and IVA-PSV from 12 to 38 weeks' gestation were developed.
Placental IVA blood flow can be visualized and quantified from early gestation in normal pregnancies using SMI. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
运用超微血管成像（SMI）技术纵向评估孕期绒毛内小动脉（IVA）的血流情况，并制定孕12至38周期间IVA搏动指数（PI）和收缩期峰值速度（PSV）的参考范围。
本研究数据源自美国国立卫生研究院资助的人类胎盘项目。纳入标准为年龄18至35岁、体重指数<30kg/m²、无合并症、单胎自然妊娠且孕周≤13⁺⁶周的女性。排除标准为母体或新生儿并发症、胎儿或脐带异常、胎盘植入异常以及孕周<37周分娩。每位参与者在孕期接受8次超声检查。使用SMI技术，在脐带插入水平的胎盘矢状切面记录所识别的IVA总数。总共测量6条IVA的PI和PSV（胎盘中央部分2条、子宫底部周边2条、子宫下段周边2条）。同时获取脐动脉（UA）-PI。运用多水平回归模型制定孕12至38周期间IVA-PI和IVA-PSV的参考范围。
共有90名女性符合研究标准。整个孕期IVA-PI逐渐降低，早孕期（12至13周）平均±标准差为1.04±0.23，孕晚期（36至37周）降至0.75±0.10。平均IVA-PSV从12至13周时的5.97±1.47cm/s增加至28至29周时的12.65±4.19cm/s，然后在整个孕晚期保持平稳，36至37周时为13.09±4.64cm/s。UA-PI在整个孕期逐渐降低，从16至17周时的1.49±0.22降至36至37周时的0.89±0.18。制定了孕12至38周期间IVA-PI和IVA-PSV的参考范围。
在正常妊娠中，使用SMI技术可在孕早期可视化并量化胎盘IVA血流情况。© 2025作者。《超声医学与妇产科学》由John Wiley & Sons Ltd代表国际妇产科超声学会出版。
