Fetal Medicine Unit, St. George's University Hospitals NHS Foundation Trust, London, UK.
Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.
Ultrasound Obstet Gynecol. 2018 May;51(5):665-671. doi: 10.1002/uog.17504. Epub 2018 Apr 2.
The main aim of this study was to construct reference ranges of maternal central hemodynamic parameters during pregnancy. The second aim was to determine the maternal and pregnancy characteristics that influence these hemodynamic parameters.
This was a prospective cohort study of low-risk pregnant women attending for routine antenatal care at St George's Hospital, London, UK. Exclusion criteria included any medical disorder present at the time of study recruitment, or development of hypertension or intrauterine fetal growth restriction following study recruitment. Stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) were obtained using non-invasive cardiac output monitoring (USCOM-1A®). USCOM-1A utilizes a non-imaging probe in the suprasternal notch to obtain velocity-time integrals of transaortic blood flow at the left ventricular outflow tract. Once the distribution of the data with respect to gestational age had been determined, maternal characteristics were added to the model to test whether they provided a significant improvement in the prediction of the median value.
The study included 627 women with a singleton pregnancy. The estimated median CO was constant for a maternal age above 32 years, but was around 0.5 L/min higher for women aged ≤ 25 years (P < 0.001). Maternal weight (P < 0.001) and height (P < 0.001) significantly affected CO values and there was a significant interaction (P = 0.002) between them. In women with a height of less than 1.60 m, there was no association between median CO and weight; however, in those with a height exceeding 1.60 m, an increase in weight was associated with an increase in CO. SV was primarily associated with height (P < 0.001), although some positive association with weight (P < 0.001) could also be observed within the normal body-mass-index range. Greater height (P < 0.001) was associated with lower median values of SVR, with an estimated difference of around 120 dynes × s/cm between 1.60 m and 1.80 m. Advancing maternal age was associated with higher median SVR, with an estimated difference of around 50 dynes × s/cm between 25 and 35 years. Smokers had a lower SVR by 73.5 (95% CI, 8.6-138.4) dynes × s/cm .
Maternal hemodynamics are influenced significantly by maternal age, height and weight. We provide USCOM-1A-specific reference ranges and a calculator for SV, CO and SVR in uncomplicated pregnancies that correct for maternal age, height and weight. This should enable clinical application and comparison in both uncomplicated and pathological pregnancies. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
本研究的主要目的是构建妊娠期间母体中心血液动力学参数的参考范围。第二个目的是确定影响这些血液动力学参数的母体和妊娠特征。
这是一项在英国伦敦圣乔治医院进行的低风险孕妇常规产前护理的前瞻性队列研究。排除标准包括在研究招募时存在任何医学疾病，或在研究招募后出现高血压或宫内胎儿生长受限。使用非侵入性心输出量监测仪（USCOM-1A®）获得每搏量（SV）、心输出量（CO）和全身血管阻力（SVR）。USCOM-1A 利用胸骨上切迹的非成像探头获得左心室流出道的主动脉血流速度时间积分。一旦确定了数据随胎龄的分布，就将母体特征添加到模型中，以检验它们是否能显著提高中位数的预测值。
该研究纳入了 627 名单胎妊娠的孕妇。对于年龄大于 32 岁的产妇，估计 CO 中位数是恒定的，但年龄小于等于 25 岁的产妇 CO 中位数高约 0.5 L/min（P<0.001）。产妇体重（P<0.001）和身高（P<0.001）显著影响 CO 值，两者之间存在显著的相互作用（P=0.002）。身高小于 1.60m 的女性中，CO 中位数与体重之间无相关性；然而，身高大于 1.60m 的女性中，体重增加与 CO 增加相关。SV 主要与身高相关（P<0.001），尽管在正常体重指数范围内也可以观察到与体重的一些正相关（P<0.001）。身高较高（P<0.001）与 SVR 的中位数较低相关，1.60m 与 1.80m 之间的估计差异约为 120 dynes×s/cm。随着产妇年龄的增长，SVR 的中位数也随之升高，25 岁至 35 岁之间的估计差异约为 50 dynes×s/cm。吸烟者的 SVR 低 73.5（95%CI，8.6-138.4）dynes×s/cm。
母体血液动力学受母体年龄、身高和体重的显著影响。我们提供了特定于 USCOM-1A 的参考范围和 SV、CO 和 SVR 的计算器，可校正母体年龄、身高和体重。这应该能够在非复杂性和病理性妊娠中进行临床应用和比较。版权所有 © 2017 ISUOG。由 John Wiley & Sons Ltd 出版。
