Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium,
Department of Obstetrics and Gynaecology, Ziekenhuis Oost-Limburg, Genk, Belgium,
Fetal Diagn Ther. 2019;46(4):238-245. doi: 10.1159/000495507. Epub 2019 Feb 6.
Pregnancies complicated with small for gestational age (SGA) neonates are reported with maternal circulatory maladaptations.
We aimed to understand the pathophysiology of the maternal circulation in normotensive SGA pregnancies and to point out the trimestral differences from those with appropriate-to-large (non-SGA [NGA]) neonates.
An observational study was conducted in 3 trimestral cohorts of normotensive pregnancies, categorized after birth according to neonatal birth weight percentile (BW%) as SGA (BW% ≤10, n = 158) or NGA (BW% > 10, n = 1,038). Standardized electrocardiogram-Doppler ultrasound, impedance cardiography, and bio-impedance were used to assess the maternal heart, arteries, veins, and fluid.
Diastolic blood pressure and mean arterial pressure were not significantly different, unless in the third trimester. In SGA compared to NGA pregnancies, total peripheral resistance (TPR) was higher and total arterial compliance, cardiac output (CO), and total body water (TBW) were lower throughout pregnancy. Venous return-enhancing functions were activated. In NGA but not SGA pregnancies, a positive correlation was found between BW% and CO + TBW and a negative correlation between BW% and TPR.
SGA pregnancies are characterized by lower maternal body fluid volume and CO, while normal blood pressures are maintained via increased TPR already from the first trimester onwards. Pregnancy-induced hemodynamic changes are superimposed on these characteristics.
患有胎儿生长受限（SGA）新生儿的妊娠会伴有母体循环适应性不良。
我们旨在了解正常血压 SGA 妊娠的母体循环病理生理学，并指出其与正常大小（非 SGA [NGA]）新生儿的妊娠在各 trimester 之间的差异。
对 3 个 trimester 的正常血压妊娠进行了一项观察性研究，根据新生儿出生体重百分位数（BW%）出生后分为 SGA（BW%≤10，n=158）或 NGA（BW%＞10，n=1038）。使用标准心电图-多普勒超声、阻抗心动图和生物阻抗来评估母体心脏、动脉、静脉和体液。
除非在第三 trimester，否则舒张压和平均动脉压没有明显差异。与 NGA 妊娠相比，SGA 妊娠中的总外周阻力（TPR）较高，而整个孕期的总动脉顺应性、心输出量（CO）和总体液（TBW）均较低。静脉回流增强功能被激活。在 NGA 但不是 SGA 妊娠中，发现 BW%与 CO+TBW 之间呈正相关，而 BW%与 TPR 之间呈负相关。
SGA 妊娠的母体体液量和 CO 较低，而正常血压通过从第一 trimester 开始增加 TPR 得以维持。妊娠引起的血流动力学变化叠加在这些特征之上。
