van Veen Teelkien R, Panerai Ronney B, Haeri Sina, van den Berg Paul P, Zeeman Gerda G, Belfort Michael A
University Medical Center Groningen, Department of Obstetrics and Gynaecology, Groningen, The Netherlands; Baylor College of Medicine, Department of Obstetrics and Gynecology, Houston, TX, USA.
Department of Cardiovascular Sciences, University of Leicester, UK; NIHR Biomedical Research Unit in Cardiovascular Sciences, Glenfield Hospital, UK.
Pregnancy Hypertens. 2016 Oct;6(4):380-383. doi: 10.1016/j.preghy.2016.08.242. Epub 2016 Aug 28.
The mechanism by which pregnancy affects the cerebral circulation is unknown, but it has a central role in the development of neurological complications in preeclampsia, which is believed to be related to impaired autoregulation. We evaluated the cerebral autoregulation in the second half of pregnancy, and compared this with a control group of healthy, fertile non-pregnant women.
In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (noninvasive arterial volume clamping), and end-tidal carbon dioxide (EtCO2) were simultaneously collected for 7min. The autoregulation index (ARI) was calculated. ARI values of 0 and 9 indicated absent and perfect autoregulation, respectively. ANOVA and Pearson's correlation coefficient were used, with p<0.05 considered significant.
A total of 76 pregnant and 18 non-pregnant women were included. The ARI did not change during pregnancy, but pregnant women had a significantly higher ARI than non-pregnant controls (ARI 6.7±0.9 vs. 5.3±1.4, p<0.001). This remained significant after adjusting for EtCO2 (p<0.001).
Cerebral autoregulation functionality is enhanced in the second half of pregnancy, when compared to non-pregnant fertile women, even after controlling for EtCO2. The autoregulation does not change with advancing gestational age.
妊娠影响脑循环的机制尚不清楚，但它在子痫前期神经并发症的发生发展中起核心作用，子痫前期被认为与自身调节受损有关。我们评估了妊娠后半期的脑自身调节功能，并将其与健康、有生育能力的非妊娠女性对照组进行比较。
在一项前瞻性队列分析中，同时收集大脑中动脉的脑血流速度（通过经颅多普勒测定）、血压（无创动脉容积钳夹法）和呼气末二氧化碳（EtCO2），持续7分钟。计算自身调节指数（ARI）。ARI值为0和9分别表示自身调节缺失和完美。采用方差分析和Pearson相关系数，p<0.05被认为具有统计学意义。
共纳入76名孕妇和18名非孕妇。妊娠期间ARI没有变化，但孕妇的ARI显著高于非妊娠对照组（ARI 6.7±0.9 vs. 5.3±1.4，p<0.001）。在调整EtCO2后，这一差异仍然显著（p<0.001）。
与非妊娠有生育能力的女性相比，即使在控制EtCO2后，妊娠后半期的脑自身调节功能仍增强。自身调节功能不会随着孕周增加而改变。
