LOW TARGET BIRTH-WEIGHT OR GROWTH-RETARDATION - UMBILICAL DOPPLER FLOW VELOCITY WAVE-FORMS AND HISTOMETRIC ANALYSIS OF FETOPLACENTAL VASCULAR TREE

OBJECTIVE: The placental vascular architecture of small-for-gestatonal -age fetuses seems to have an impact on the flow patterns in the umbil ical arteries. STUDY DESIGN: Blood flow velocity waveforms of the umbi lical arteries were measured by Doppler ultrasonography in nine small- for-gestational-age fetuses with elevated systolic/diastolic ratios of the umbilical arteries, seven small-for-gestational-age fetuses with normal flow patterns, and 14 appropriate-for-gestational-age fetuses w ith normal flow patterns. After delivery histomorphometric placental i nvestigations were performed. RESULTS: Reduced end-diastolic flow velo cities were significantly associated with both a reduction of vascular ization within the terminal villi and adverse diffusion conditions, in dicating insufficient functional maturity. The perfusion and diffusion capacity of small-for-gestational-age placentas with normal umbilical artery flow velocity waveforms was similar or even slightly better co mpared with the appropriate-for-gestational-age control values. CONCLU SION: These data suggest that Doppler flow velocimetry in the umbilica l arteries is predictive of a vascular lesion within the placentas of small-for-gestational-age fetuses.