Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, University of Toronto, 60 Grosvenor Street, Toronto, Ontario, Canada.
Am J Obstet Gynecol. 2010 Nov;203(5):475.e1-6. doi: 10.1016/j.ajog.2010.05.031.
Pregnancy is associated with substantial changes in the maternal circulatory physiology. Our aim was to investigate maternal cerebral blood flow (CBF) during normal pregnancies.
We prospectively measured maternal CBF in 210 low-risk pregnant women at different gestational ages, and in 15 nonpregnant women. CBF was assessed by measuring blood flow volume in the internal carotid artery (ICA) by dual-beam angle-independent digital Doppler ultrasound.
ICA blood flow volume increased during pregnancy from 318 mL/min ± 40.6 mL/min in the first trimester to 382.1 mL/min ± 50.0 mL/min during the third trimester, corresponding to CBF values of 44.4 and 51.8 mL/min(-1)/100 g(-1), respectively (P < .0001). CBF changes were associated with progressive decrease in cerebral vascular resistance and moderate increase in ICA diameter.
Maternal CBF is gradually increasing during normal pregnancy. Vasorelaxing impact of estrogens and other factors on cerebral vessels may explain the changes in CBF during pregnancy.
妊娠会引起母体循环生理学的重大变化。我们的目的是研究正常妊娠期间的母体脑血流（CBF）。
我们前瞻性地测量了 210 名低危孕妇在不同妊娠周数和 15 名未怀孕妇女的母体 CBF。通过双束角独立数字多普勒超声测量颈内动脉（ICA）的血流体积来评估 CBF。
ICA 血流体积在妊娠期间增加，从第一孕期的 318 mL/min ± 40.6 mL/min 增加到第三孕期的 382.1 mL/min ± 50.0 mL/min，相应的 CBF 值分别为 44.4 和 51.8 mL/min(-1)/100 g(-1)（P<.0001）。CBF 变化与脑血管阻力逐渐降低和 ICA 直径适度增加有关。
正常妊娠期间母体 CBF 逐渐增加。雌激素和其他因素对脑血管的舒张作用可能解释了妊娠期间 CBF 的变化。
