Chapman A B, Abraham W T, Zamudio S, Coffin C, Merouani A, Young D, Johnson A, Osorio F, Goldberg C, Moore L G, Dahms T, Schrier R W
Department of Medicine, University of Colorado Health Sciences Center, St. Louis, Missouri, USA.
Kidney Int. 1998 Dec;54(6):2056-63. doi: 10.1046/j.1523-1755.1998.00217.x.
The systemic hemodynamic profile of human pregnancy is characterized by a decrease in mean arterial pressure, a rise in cardiac output and plasma volume in association with an increase in renal plasma flow and glomerular filtration rate. The factors and the time course responsible for the initial hemodynamic changes seen in human pregnancy have not been completely documented. We hypothesize that systemic and renal hemodynamic changes occur early, prior to the presence of the fetal-placental unit.
Thirteen women were studied prior to and immediately following conception in identical fashion at gestational weeks 6, 8, 10, 12, 24 and 36. Individuals underwent mean arterial pressure, cardiac output, inulin and PAH clearance determinations.
Mean arterial pressure decreased by six weeks gestation (mid follicular 81.5 +/- 2.6 vs. six weeks 68.7 +/- 2.0 mm tig, P < 0.001) in association with a significant increase in cardiac output, a decrease in systemic vascular resistance and an increase in plasma volume. Renal plasma flow and glomerular filtration rate increased by six weeks gestation. Plasma renin activity and aldosterone concentration increased significantly by six weeks, whereas norepinephrine levels did not change throughout pregnancy. Atrial natriuretic peptide levels increased later, at 12 weeks gestation. Plasma cGMP levels decreased and cGMP clearance increased by six and eight weeks, respectively.
Peripheral vasodilation occurs early in pregnancy prior to full placentation in association with renal vasodilation and activation of the renin-angiotensin-aldosterone system. Plasma volume expansion occurs early, followed later by increases in ANP concentration, suggesting that ANP increases in response to changes in intravasular volume.
人类孕期的全身血流动力学特征为平均动脉压降低、心输出量增加、血浆量增加，同时肾血浆流量和肾小球滤过率升高。导致人类孕期出现初始血流动力学变化的因素及时间进程尚未完全明确。我们推测全身和肾脏血流动力学变化在胎儿 - 胎盘单位形成之前就已早期发生。
对13名女性在妊娠前及妊娠后第6、8、10、12、24和36周以相同方式进行研究。受试者接受平均动脉压、心输出量、菊粉和对氨基马尿酸清除率测定。
妊娠6周时平均动脉压下降（卵泡中期81.5±2.6 vs. 6周时68.7±2.0 mmHg，P<0.001），同时心输出量显著增加、全身血管阻力降低、血浆量增加。妊娠6周时肾血浆流量和肾小球滤过率升高。血浆肾素活性和醛固酮浓度在6周时显著升高，而去甲肾上腺素水平在整个孕期未发生变化。心房利钠肽水平在妊娠12周时升高。血浆cGMP水平分别在6周和8周时降低和清除率增加。
妊娠早期在胎盘完全形成之前就出现外周血管舒张，同时伴有肾血管舒张和肾素 - 血管紧张素 - 醛固酮系统激活。血浆量早期扩张，随后心房利钠肽浓度升高，提示心房利钠肽升高是对血管内容量变化的反应。
