POLYNOMIAL ANALYSIS OF PLACENTAL FLOW PATTERNS IN GROWTH-RETARDED FETUSES

Correct interpretation of conspicuous blood flow velocity waveforms ca nnot rely solely on the evaluation of uteroplacental vascular Doppler flow patterns by means of angle-independent indices such as the resist ance or pulsatility index. In addition to the degree of pulsatility, t he waveform shape between the systolic and diastolic peak values is of considerable consequence. A subdivision of the total flow waveform in to orthogonal polynomial components allows both pulsatility evaluation and notching to be registered, providing a higher sensitivity in iden tification of pathological vascular resistance. Accurate recording and assessment of the flow waveform is therefore an important qualitative criterion for the classification of Doppler flow patterns in pregnanc ies with reduced uteroplacental perfusion.