妊娠期间的生理变化,使心脏负荷加重,随着妊娠的进展孕产妇血液动力学发生巨大改变。了解妊娠期、分娩期和产褥期心血管系统适应性改变是正确和合理的处理正常妊娠和心脏病孕妇的基础。一、正常妊娠期心脏和血液动力学变化 (一)妊娠期孕妇体内循环血容量随孕月而逐渐增加,多数学者报道:血容量从10孕周即开始增加,至20～24孕周血浆容量增加迅速,较未孕期增加34％,以后稳定增加,但有明显的个体差异,从增加30～100％不等。一般增加30～50％,这相当于总血容量从平均约4000ml增加至5800ml。经产妇增加较初产妇多,初产妇增加平均为3850ml,增加40％,经产妇增加平均为4100ml,增加57％;双胎妊娠增加较单胎妊娠为多,后者血容量较前者多10ml/kg体重。血容量的增加以血浆容量为主,约增加40～60％,而红细胞增加10～15％,因而红细胞、红细胞容积及血色素相对下降,故血液稀释。从而引起血红蛋白浓度下降,称之为“妊娠期生理性贫血”。红细胞容积从非孕期40％降至33％,血红蛋白降至11～12g/100ml,血沉加速。以上的变化降低了血液粘稠度,对孕期血液循环是一有利条件。孕期全身水和钠有所潴留:一般孕期总体液量平均增加8.5L,根据孕妇水肿的有无,液体潴留,个体差异极大,其变异系数高达34％,孕期水代谢的特点:是总体液的增加伴有等渗盐的增加,整个 Physiological changes during pregnancy, the heart load increased, with the progress of pregnancy, maternal hemodynamics have changed dramatically. Understanding the changes in cardiovascular fitness during pregnancy, childbirth and the puerperium is the correct and logical basis for treating pregnant women with normal pregnancy and heart disease. First, the normal heart and hemodynamic changes during pregnancy (a) of pregnant women during pregnancy blood volume increased gradually with the month of pregnancy, most scholars have reported: blood volume began to increase from 10 weeks to 20 weeks to 24 weeks of pregnancy plasma volume Increased rapidly, an increase of 34% compared with non-pregnancy, after a steady increase, but there are significant individual differences, from an increase of 30 to 100%. The general increase of 30 ~ 50%, which is equivalent to the total blood volume increased from an average of about 4000ml to 5800ml. The mothers increased more than the first maternal, primipara increased an average of 3850ml, an increase of 40%, an average increase of 4100ml by maternal, an increase of 57%; twin pregnancies increased more than singleton pregnancies, the latter more than the former blood volume of 10ml / kg body weight. Increased blood volume to the main plasma volume, an increase of about 40 to 60%, while the red blood cells increased by 10 to 15%, so the red blood cells, red blood cell volume and hemoglobin relative decline, so hemodilution. Causing a decrease in hemoglobin concentration, known as “physiological anemia during pregnancy.” Red blood cell volume decreased from 40% during non-pregnancy to 33%, hemoglobin dropped to 11 ~ 12g / 100ml, erythrocyte sedimentation rate accelerated. Changes in the above lower blood viscosity, blood circulation during pregnancy is a favorable condition. During pregnancy, there is retention of water and sodium in the body: the average volume of general fluid during pregnancy increases by an average of 8.5L. According to the presence or absence of edema in pregnant women, there is a great difference between individuals. The coefficient of variation is as high as 34%. The characteristics of water metabolism during pregnancy are: The increase is accompanied by an increase in isotonic salt throughout