Cardiac output and plasma brain natriuretic peptide are changed and correlated in normal pregnancy and labor

WU Shu-yan; ZHANG Jian-ping

摘要：Background Continuous cardiac output(CO) monitoring and plasma brain natriuretic peptide(BNP) measurement enable clinicians to better understand patients' hemodynamics.However,the trend of CO and plasma BNP in normal pregnant and labor women and their correlation are seldomly studied.Methods Ninety-two womenscheduled for vaginal delivery were enrolled in this observational study.A non-invasive CO monitor incorporating the electrical velocimetry algorithm was used to measure CO at pre-defined time points during labor.At the same time,plasma BNP values were determined by using a standard assay.The changes of CO and plasma BNP at pre-defined time points and caused by phenylephrine administration were analyzed.The CO and plasma BNP of forty-four non-pregnant women whom were randomly selected as control group were also analyzed.Results The level of CO in normal pregnancy was higher than that in non-pregnancy and in late pregnancy (P ＜ 0.05).It increased gradually during uterine contraction,reached to the peak value before delivery,and decreased gradually after delivery,approaching the level in late pregnancy (P ＞ 0.0,5),but higher than that in non-pregnancy(P ＜ 0.05).Plasma BNP had the same trend of CO.There was a positive correlation between them (r =0.29,P ＜ 0.01).Conclusion The cardiac burden is increased significantly during pregnancy and labor,especially in the second stage of labor.