Connors G, Gillis S, Hunse C, Gagnon R, Richardson B
Lawson Research Institute, St. Joseph's Health Centre, London, Ontario, Canada.
J Dev Physiol. 1991 Jun;15(6):331-6.
The association and possible interactions of fetal behavioural state, fetal heart rate and vascular resistance was studied in 23 healthy pregnant women between 36 and 40 weeks' gestation. Doppler flow velocity waveforms were obtained from fetal cerebral (anterior cerebral, internal carotid and basilar), descending aorta and umbilical arteries during fetal behavioural state 1F and repeated during 2F. The Resistance Index (RI) was used as a measure of vascular resistance. Decreased vascular resistance was observed in all vessels except the umbilical artery during fetal behavioural state 2F compared to 1F (P less than 0.001). A significant interaction was observed between fetal heart rate and fetal behavioural state on the RI of the vessels studied, with a greater negative slope for RI plotted against fetal heart rate in fetal behavioural state 2F (-0.00139) compared to 1F (0.00005) (P less than 0.001). We conclude that the transition from fetal behavioural state 1F to 2F is associated with a significant reduction in cerebral and systemic vascular resistance, with no apparent change in placental resistance. Furthermore, fetal behavioural state and fetal heart rate interact, demonstrating a stronger association of fetal heart rate and RI in fetal behavioural state 2F in keeping with an increase in baroreflex sensitivity at this time.
对23名妊娠36至40周的健康孕妇，研究了胎儿行为状态、胎儿心率和血管阻力之间的关联及可能的相互作用。在胎儿行为状态1F期间，从胎儿大脑（大脑前动脉、颈内动脉和基底动脉）、降主动脉和脐动脉获取多普勒血流速度波形，并在胎儿行为状态2F期间重复获取。阻力指数（RI）用作血管阻力的度量指标。与胎儿行为状态1F相比，在胎儿行为状态2F期间，除脐动脉外的所有血管均观察到血管阻力降低（P小于0.001）。在所研究血管的RI方面，观察到胎儿心率与胎儿行为状态之间存在显著相互作用，与胎儿行为状态1F（0.00005）相比，胎儿行为状态2F中RI相对于胎儿心率绘制的负斜率更大（-0.00139）（P小于0.001）。我们得出结论，从胎儿行为状态1F到2F的转变与大脑和全身血管阻力的显著降低相关，胎盘阻力无明显变化。此外，胎儿行为状态和胎儿心率相互作用，表明在胎儿行为状态2F中胎儿心率与RI的关联更强，这与此时压力反射敏感性增加一致。
