This study investigated the relationships between maternal and fetal hemodynamics in a population with suspected fetal growth restriction.
This was a prospective study of normotensive pregnancies referred to our outpatient clinic for a suspected fetal growth restriction. Maternal hemodynamics measurement was performed, using a noninvasive device (USCOM-1A) and a fetal ultrasound evaluation to assess fetal biometry and velocimetry Doppler parameters. Comparisons among groups were performed with 1-way analysis of variance with Student-Newman-Keuls correction for multiple comparisons and with Kruskal-Wallis test where appropriate. The Spearman rank coefficient was used to assess the correlation between maternal and fetal hemodynamics. Pregnancies were observed until delivery.
A total of 182 normotensive pregnancies were included. After the evaluation, 54 fetuses were classified as growth restricted, 42 as small for gestational age, and 86 as adequate for gestational age. The fetus with fetal growth restriction had significantly lower umbilical vein diameter (P<.0001), umbilical vein velocity (P=.02), umbilical vein flow (P<.0001), and umbilical vein flow corrected for fetal weight (P<.01) than adequate-for-gestational-age and small-for-gestational-age fetuses. The maternal hemodynamic profile in fetal growth restriction was characterized by elevated systemic vascular resistance and reduced cardiac output. The umbilical vein diameter was positively correlated to maternal cardiac output (rs=0.261), whereas there was a negative correlation between maternal systemic vascular resistance (rs=-0.338) and maternal potential energy-to-kinetic energy ratio (rs=-0267). The fetal umbilical vein time averaged max velocity was positively correlated to maternal cardiac output (rs=0.189) and maternal inotropy index (rs=0.162), whereas there was a negative correlation with maternal systemic vascular resistance (rs=-0.264) and maternal potential energy-to-kinetic energy ratio (rs=-0.171). The fetal umbilical vein flow and the flow corrected for estimated fetal weight were positively correlated with maternal cardiac output (rs=0.339 and rs=0.297) and maternal inotropy index (rs=0.217 and r=0.336), whereas there was a negative correlation between maternal systemic vascular resistance (rs=-0.461 and rs=-0.409) and maternal potential energy-to-kinetic energy ratio (rs=-0.336 and rs=-0.408).
Maternal and fetal hemodynamic parameters were different in the 3 groups of fetuses: fetal growth restriction, small for gestational age, and adequate for gestational age. Maternal hemodynamic parameters were closely and continuously correlated with fetal hemodynamic features. In particular, a maternal hemodynamic profile with high systemic vascular resistance, low cardiac output, reduced inotropism, and hypodynamic circulation was correlated with a reduced umbilical vein flow and increased umbilical artery pulsatility index. The mother, placenta, and fetus should be considered as a single cardiac-fetal-placental unit. The correlations of systemic vascular resistance, cardiac output, and inotropy index with umbilical artery impedance indicate the key role of these 3 parameters in placental vascular tree development. The umbilical vein flow rate and, therefore, the placental perfusion seems to be influenced not only by these three parameters but also by the maternal cardiovascular kinetic energy.
目的:本研究调查了疑似胎儿生长受限人群中母体和胎儿血流动力学之间的关系。
方法:这是一项前瞻性研究,研究对象是因疑似胎儿生长受限而转诊至门诊的正常血压妊娠。进行母体血流动力学测量,使用非侵入性装置(USCOM-1A)和胎儿超声评估来评估胎儿生物测量和测速多普勒参数。进行组间比较,采用单因素方差分析,对多重比较进行Student-Newman-Keuls校正,并在适当的情况下进行Kruskal-Wallis检验。Spearman秩系数用于评估母体和胎儿血流动力学之间的相关性。观察到怀孕直到分娩。
结果:共纳入182例血压正常的妊娠。经过评估,54个胎儿被归类为生长受限,42小于胎龄,和86适合胎龄。胎儿生长受限的胎儿脐静脉直径显著降低(P<0.0001),脐静脉速度(P=.02),脐静脉流量(P<0.0001),和脐静脉血流校正胎儿体重(P<.01)比适合胎龄和小于胎龄的胎儿。胎儿生长受限的母体血流动力学特征是全身血管阻力升高和心输出量减少。脐静脉内径与产妇心输出量呈正相关(rs=0.261),而母体全身血管阻力(rs=-0.338)与母体势能-动能比(rs=-0267)之间呈负相关。胎儿脐静脉时间平均最大速度与母体心输出量(rs=0.189)和母体收缩指数(rs=0.162)呈正相关,而与母体全身血管阻力(rs=-0.264)和母体势能与动能之比(rs=-0.171)呈负相关。胎儿脐静脉流量和根据估计胎儿体重校正的流量与母体心输出量(rs=0.339和rs=0.297)和母体收缩指数(rs=0.217和r=0.336)呈正相关,而母体全身血管阻力(rs=-0.461和rs=-0.409)与母体势能-动能比(rs=-0.336和rs=-0.408)之间呈负相关。
结论:3组胎儿的母胎血流动力学参数不同:胎儿生长受限,小于胎龄,并且适合胎龄。母体血流动力学参数与胎儿血流动力学特征密切相关且持续相关。特别是,具有高全身血管阻力的母体血流动力学特征,低心输出量,减少的肌力倾向,低动力循环与脐静脉流量减少和脐动脉搏动指数增加有关。母亲,胎盘,和胎儿应被视为一个单一的心脏-胎儿-胎盘单位。全身血管阻力的相关性,心输出量,和脐动脉阻抗的肌力指数表明这3个参数在胎盘血管树发育中的关键作用。脐静脉流速和,因此,胎盘灌注似乎不仅受这三个参数的影响,而且受母体心血管动能的影响。