Cerebral artery Doppler	Group						X² P
Cerebral artery Doppler	Severe		Moderate		Mild		X² P
Abnormal	4	36.4	0	0.0	0	0.0	24.218 0.001*
Normal	7	63.6	23	100.0	40	100.0	24.218 0.001*
Total	4	5.4	70	94.6	74	100.0