[The observation of the maternal hemodynamics during labor and cesarean section (author's transl)]

Abstract

The echocardiographic observation of the maternal hemodynamics was performed in 12 normal parturient women during labor and 10 patients during cesarean section. In the first stage of labor, the increase of cardiac output volume (CO) was observed during contraction as compared with that between contraction. And this increase of CO was due to the increase of heart rate (HR) t 4-5cm dilatation of cervix, and the increase of stroke volume (SV) at 7-8cm dilatation of cervix. In the second stage of labor, the increase of HR and mean velocity of circumferential fiber shortening (mVcf), and the decrease of ejection time, end-diastolic volume, SV, CO and ejection fraction (EF) were observed during contraction with expulsive efforts as compared with those in late pregnancy. These changes suggest that the severe hypovolemic stress is imposed, which may be caused by a decrease of venous return. The increase of HR and the decrease of SV, CO, EF, mVcf and LAD were observed 15 minutes after the epidural anesthesia as compared with those in late pregnancy, and these changes also suggest that the hypovolemic stress is imposed, which may depend on a decrease of venous return. The increase of CO was observed 3 and 5 minutes after delivery in labor and cesarean section as compared with those in late pregnancy. This increase of CO was due to the increase of HR and SV in labor, and the increase of HR in cesarean section. Consequently, the changes of maternal hemodynamics during labor imply to be greater than those during cesarean section, and this may depend on such factors as pains, expulsive efforts and cyclic blood volume redistribution during labor.