Publications of Faculty of Medicine:Middle Cereberal Artery Flow Velocity Waveforms in Normal and Small for Gestational Age Fetuses: Abstract

Middle Cereberal Artery Flow Velocity Waveforms in Normal and Small for Gestational Age Fetuses
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Duplux Doppler sonograpby is an important diagnostic tool in modem obestetrices and its contributions to the assessment of small for gestational age (SGA) foetus can no longer be ignorred. The middle cereberal artery (MCA) flow velocity waveforms were obtained in 16 normal fetuses, the pulsatility index (PI) values of their MCA were higher at 25 to 30 weeks gestation than those observed during the two periods of major cereberal cellular multiplication in the human foetus (i.e 15-20 weeks and at end of gestation). The PI of the MCA was also deter mined in 33 SGA fetuses. A middle cereberai artery PI value below our normal range was re corded in 9 of the 33 smail-for-gestational age fetuses (27.3 %). These SGA fetuses with ab- ' normal PI value had a significantly higher incidence of abnormal foetal heart rate and was admitted into the neonatal intensive care unit. There were 3 deaths in 9 of SGA fetuses (33.3%) with abnormal low middle cereberal aretery PI, and 3 deaths In 24 small-forgestational age fetuses (12.5 %) with normal MCA pulsatility index values. The PI sensitivi ty and specificity; predictive validity for adverse perinatal outcome; calculated results are 67% and 84 % respectively. Our data indicate that the PI of the MCA in the normal human foetus has a parabolic pat tern between 15-20 weeks and at late in the third trimester of gestation. Also, the results sug gest that the SGA fetuses with a normal middle cereberal artery PI is at lower risk than the fe tuses with abnormal PI values. Moreover, management of SGA fetuses may be aided by the study of their MCA waveforms.