Fewell J E
Department of Medical Physiology, University of Calgary, Alberta, Canada.
Am J Physiol. 1995 Apr;268(4 Pt 2):H1734-9. doi: 10.1152/ajpheart.1995.268.4.H1734.
Little is known about the influence of sleep on systemic and uteroplacental hemodynamics during pregnancy. Experiments were therefore carried out on six chronically instrumented pregnant ewes (125-133 days of gestation) to investigate the influence of sleep on systemic and uteroplacental hemodynamics. Because nonlabor myometrial activity influences uteroplacental hemodynamics, we made measurements during quiet wakefulness, quiet sleep, and active sleep in the presence and absence of myometrial activity. Cardiac output, heart rate, and systemic arterial pressure were decreased in active sleep compared with quiet wakefulness; these variables were not significantly altered by myometrial activity. The interaction between sleep and myometrial activity was such that the lowest values of uteroplacental blood flow, as estimated from middle uterine artery blood flow to the pregnant uterine horn and, hence, uteroplacental oxygen delivery occurred during active sleep in the presence of myometrial activity (i.e., decreased approximately 19% compared with quiet wakefulness and the absence of myometrial activity). Further investigation is required to determine the possible fetal consequences of a reduced uteroplacental perfusion in the presence of myometrial activity during sleep.
关于睡眠对孕期全身及子宫胎盘血流动力学的影响，目前所知甚少。因此，我们对六只长期植入仪器的怀孕母羊（妊娠125 - 133天）进行了实验，以研究睡眠对全身及子宫胎盘血流动力学的影响。由于非分娩时子宫肌层活动会影响子宫胎盘血流动力学，我们在有或无子宫肌层活动的情况下，分别在安静觉醒、安静睡眠和活跃睡眠期间进行了测量。与安静觉醒相比，活跃睡眠时心输出量、心率和全身动脉压均降低；这些变量并未因子宫肌层活动而发生显著改变。睡眠与子宫肌层活动之间的相互作用使得，根据子宫中动脉向妊娠子宫角的血流估算的子宫胎盘血流量的最低值，进而子宫胎盘氧输送量，出现在存在子宫肌层活动的活跃睡眠期间（即与安静觉醒且无子宫肌层活动相比，降低了约19%）。需要进一步研究来确定睡眠期间存在子宫肌层活动时子宫胎盘灌注减少可能对胎儿产生的后果。
