The fetal cardiovascular function in chronic placental insufficiency is different from experimental hypoxia.
Ten mothers at normal term pregnancy were rendered mildly hypoxic by allowing them to breathe a gas mixture of 10% oxygen and 90% nitrogen. The fetuses were studied with Doppler ultrasound and computer assisted cardiotocography. There was vasodilatation in the cerebral vasculature while the utero-placental blood flow decreased. No changes in fetal haemodynamics occurred. The fetal heart rate was correlated inversely to the heart rate variation. There was a positive correlation between the heart rate variation and the umbilical flow velocity waveform index. In a group of 30 subjects with severe pre-eclampsia and/or severe intrauterine growth retardation, the fetal heart rate variation was inversely correlated to the umbilical blood flow. Hence, the study shows a clear physiological difference in fetal heart function during short-term hypoxia compared to that during long term placental insufficiency.
Erkkola
R
R
Department of Obstetrics and Gynaecology, Turku University Central Hospital, Finland.
Pirhonen
J
J
Polvi
H
H
D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000503:physiopathology; D005311:Fetal Hypoxia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005333:Fetus / Q000098:blood supply; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange / Q000502:physiology*; D010927:Placental Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging / Q000503:physiopathology; D011247:Pregnancy; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D016216:Ultrasonography, Prenatal