Temporal relationships between hormonal and hemodynamic changes in early human pregnancy
Temporal relationships between hormonal and hemodynamic changes in early human pregnancy
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DOI：
10.1046/j.1523-1755.1998.00217.x
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发表时间：
1998-12-01
影响因子：
19.6
通讯作者：
Schrier, RW
中科院分区：
文献类型：
--
作者：
Chapman, AB;Abraham, WT;Schrier, RW
背景人类妊娠的全身血流动力学特征是平均动脉压降低，心输出量和血浆容量增加，同时肾血浆流量和肾小球滤过率增加。导致人类妊娠早期血流动力学变化的因素和时间进程尚未完全被记录在案。我们假设全身和肾脏的血流动力学改变发生在胎儿-胎盘单位出现之前的早期。13名妇女在怀孕前和怀孕后立即以相同的方式在怀孕6、8、10、12、24和36周进行了研究。受试者接受了平均动脉压、心输出量、菊糖和多环芳烃清除量的测定。平均动脉压在妊娠6周时降低(卵泡中期81.5+/-2.6vs.68.7+/-2.0 mm tig，P<；0.001)，同时心输出量显著增加，全身血管阻力减少，血浆容量增加。妊娠6周时，肾血浆流量和肾小球滤过率均增加。血浆肾素活性和醛固酮浓度在怀孕6周后显著增加，而去甲肾上腺素水平在整个妊娠期间没有变化。心钠素水平在妊娠12周后升高。治疗后6周和8周，血浆cGMP水平下降，cGMP清除率增加。外周血管扩张发生在妊娠早期，伴随着肾血管扩张和肾素-血管紧张素-醛固酮系统的激活。血浆容量扩张发生在早期，随后ANP浓度升高，这表明ANP增加是对血管内容量变化的反应。
Background 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.Methods. 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.Results. 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 tate increased by six weeks gestation. Plasma renin activity and aldosterone concentration increased significently 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.Conclusions. Peripheral vasodilation occurs early in pregnancy Drier 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.