FETAL HEART-RATE AND DOPPLER FLOW PARAMETER IN FETAL VESSELS - ANALYSIS OF 2517 DOPPLER SIGNALS

Analysis of more than 2500 doppler flow signals in three patients was performed to evaluate the influence of fetal heart rate (fhr) variatio n on S/D-ratio in fetal vessels. Little differences of S/D-ratio in fe tal vessels (descending aorta, umbilical arteries) were detected withi n the physiological variations of fhr (120-160 bpm) (envelope of regre ssion line -0.007, -0.006). Analysing inter- as well as intraindividua l variation only minor effects of fhr alteration can be observed in cl inical application of doppler flow velocimetry. Dopplersonographic mea surements, however, should be performed for at least a three minute pe riod (for each vessel) to avoid false-positive or false-negative inter pretation of short term changes of doppler signals. This is especially important in distressed fetuses.