The effect of fetal behavioral states on middle cerebral artery peak systolic velocity

Objective This study was undertaken to determine whether is there a difference in the middle cerebral artery peak systolic velocity (MCA PSV) between active and resting behavioral states in healthy fetuses aged 30 to 32 weeks. Methods MCA blood flow was measured by pulsed Doppler sonography 3 times during each fetal behavioral state (active and resting). The average during active state was compared during the resting state. Statistical analysis was performed by paired t test. Results During the fetal active state, there was a significant increase in the mean PSV (51.59 cm/s vs 46.95 cm/s, P< .0001) and mean end-diastolic velocity (9.59 cm/s vs 7.98 cm/s, P = .0015), and a significant decrease in the mean pulsatility index (PI) (2.07 vs 2.19, P = .0226) and the mean resistance index (0.83 vs 0.85, P = .0481). Conclusion Healthy preterm fetuses have a significantly higher MCA PSV during the active state. Activity state should be considered when interpreting MCA Doppler indices.