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Ventriculovascular physiology of the growth‐restricted fetus
Author(s) -
Gardiner H.,
Brodszki J.,
Maršál K.
Publication year - 2001
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.2001.00436.x
Subject(s) - medicine , fetus , gestational age , gestation , pulse wave velocity , cardiology , inferior vena cava , intrauterine growth restriction , birth weight , preload , obstetrics , pregnancy , hemodynamics , blood pressure , biology , genetics
Objectives To examine the mechanisms by which intrauterine growth restriction may influence later cardiovascular risk by comparing the ventriculovascular physiology of gestational age‐ and weight‐matched growth‐restricted and normal fetuses. Design A prospective longitudinal observational study of 20 normal fetuses studied from 20 weeks to term at monthly intervals was compared with a growth‐restricted cohort examined in the interval between diagnosis and delivery. The last values before delivery of the growth‐restricted cohort were compared with the normal cohort in two analyses matched for weight and for gestation. Arterial and venous vessel wall physiology and aortic pulse wave velocity were examined longitudinally in the thoracic descending aorta and inferior vena cava using an ultrasonic phase‐locked echo‐tracking system. Serial echocardiographic examinations were performed assessing structure, ventricular dimensions, function and Doppler flows. Results There was a linear increase in cardiac preload and relative pulse amplitude in the inferior vena cava with gestation. In normal fetuses, the aortic pulse wave velocity, maximum incremental and late decremental velocities increased with gestation whilst the relative pulse amplitude decreased reflecting falling distal impedance. In both age‐ and weight‐matched analyses, the growth‐restricted fetuses showed significantly reduced values reflecting the chronic fetal ventriculovascular responses to increased placental impedance. Pulse wave velocity increased with gestation and was significantly less in the growth‐restricted cohort. Conclusions Growth restriction is associated with abnormal ventriculovascular physiology that represents a successful adaptive response to raised placental impedance and reduction in wall stress as evidenced by the lower fetal pulse wave velocity in growth‐restricted fetuses. However, whilst fetal adaptive mechanisms may aid survival they may result in cerebral and vascular abnormalities that prejudice later cardiovascular health. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology