A classification of patterns of fetal middle cerebral artery velocity waveforms as seen on Doppler ultrasound

To identify, classify, and study the clinical significance of different patterns of fetal middle cerebral artery peak systolic velocity waveforms that can be seen on Doppler ultrasound.

The patterns of fetal middle cerebral artery (MCA) velocity waveforms encountered in our study (n = 1128) conducted on a rural obstetric population were analyzed.

Broadly, three different waveform-patterns (type I to type III) were identified from 1100 cases on which satisfactory studies were conducted. Types IA and IB were found in normal fetuses of the first (n = 254, 23.1 %) and second (n = 386, 35.1 %) trimesters, respectively. Type IC (n = 418, 38 %) included normal fetuses in the second (n = 25) and third (n = 317) trimesters, and 76 of 118 IUGR fetuses. Type II consisted of IUGR category; 17 (1.5 %) cases in type IIA, 10 (0.9 %) in IIB, and 11 (1.0 %) in IIC. Type III (n = 4, 0.4 %) was found in the critical cases with severe anemia secondary to feto-maternal hemorrhage.

Although different patterns of uterine and umbilical artery velocity waveforms have been described in the obstetric literature, there is no mention of patterns of fetal MCA velocity waveforms. This is the first study to demonstrate, classify, and state the clinical significance of different patterns of fetal middle cerebral artery peak systolic velocity waveforms.