Program for Pregnancy and Postpartum Health, Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.
Department of Kinesiology, Faculty of Medicine, Université Laval, Québec City, Québec, Canada.
J Appl Physiol (1985). 2022 Jan 1;132(1):247-260. doi: 10.1152/japplphysiol.00446.2021. Epub 2021 Nov 24.
We performed a randomized controlled trial measuring dynamic cerebral autoregulation (dCA) using a sit-to-stand maneuver before (SS1) and following (SS2) an acute exercise test at 16-20 wk gestation (trimester 2, TM2) and then again at 34-37 wk gestation (third trimester, TM3). Following the first assessment, women were randomized into exercise training or control (standard care) groups; women in the exercise training group were prescribed moderate intensity aerobic exercise for 25-40 min on 3-4 days per week for 14 ± 1 wk. Resting seated mean blood velocity in the middle cerebral artery (MCAv) was lower in TM3 than in TM2 but not impacted by exercise training intervention. No metric of dCA was impacted by gestational age or exercise training during SS1. During SS2, there were greater absolute and relative decreases in mean arterial blood pressure (MAP) and MCAv, but this was not impacted by the intervention. There was also no difference in the relationship between the decrease in MCAv compared with the decrease in MAP (%/%) or the onset of the regulatory response with respect to acute exercise, gestational age, or intervention; however, rate of regulation was faster in women in the exercise group following acute exercise (interaction effect, = 0.048). These data highlight the resilience of the cerebral circulation in that dCA was well maintained or improved in healthy pregnant women between TM2 and TM3. However, future work addressing the impact of acute and chronic exercise on dCA in women who are at risk for cardiovascular complications during pregnancy is needed. These data represent the first assessments of dynamic cerebral autoregulation in pregnancy using a sit-to-stand. We used a randomized controlled trial to show dynamic cerebral autoregulation is not impacted by gestational age or by chronic exercise. However, there are larger decreases in blood pressure and cerebral blood velocity following sit-to-stand after acute exercise without adverse events. These data highlight the adaptability of the cerebral circulation during pregnancy to accommodate large changes in the cardiovascular system.
我们进行了一项随机对照试验，在 16-20 孕周（第二孕期，TM2）和 34-37 孕周（第三孕期，TM3）进行急性运动试验前后（SS1 和 SS2），通过坐姿到站姿的运动来测量动态脑自动调节（dCA）。首次评估后，女性被随机分为运动训练组或对照组（标准护理）；运动训练组的女性被规定每周进行 3-4 天、每次 25-40 分钟的中等强度有氧运动，持续 14±1 周。TM3 时，大脑中动脉（MCAv）的静息坐姿平均血流速度低于 TM2，但不受运动训练干预的影响。在 SS1 期间，dCA 的任何指标都不受孕龄或运动训练的影响。在 SS2 期间，平均动脉血压（MAP）和 MCAv 的绝对和相对下降幅度更大，但干预对此没有影响。MCAv 与 MAP 下降的关系（%/%)或调节反应的起始时间与急性运动、孕龄或干预无关；然而，急性运动后，运动组女性的调节速度更快（交互效应，=0.048）。这些数据突出了脑循环的弹性，即 dCA 在健康孕妇从 TM2 到 TM3 期间得到很好的维持或改善。然而，需要进一步的研究来评估急性和慢性运动对妊娠期间心血管并发症风险妇女的 dCA 的影响。这些数据代表了使用坐姿到站姿对妊娠期间动态脑自动调节的首次评估。我们使用随机对照试验表明，dCA 不受孕龄或慢性运动的影响。然而，急性运动后，坐姿到站姿时血压和脑血流速度的下降幅度更大，但没有不良事件。这些数据突出了妊娠期间脑循环对心血管系统大变化的适应性。
