Adrenal artery velocity waveforms in the appropriate and small‐for‐gestational‐age fetus

Abstract

The purpose of this study was to compare adrenal artery flow velocity waveforms in the appropriately grown and the small-for-gestational-age fetus. Adrenal artery flow velocity waveforms were prospectively obtained from 131 appropriate- and 21 small-for-gestational-age fetuses with pulsed Doppler ultrasonography. The success rate in recording the adrenal artery was 84% (131/155) and 100% in the appropriate- and small-for-gestational-age fetuses, respectively. The pulsatility index (PI) was used to quantify the waveforms. The PI in the appropriate-for-gestational-age fetuses decreased linearly with gestational age (PI = 1.7-0.016 x gestational age). In ten small-for-gestational-age fetuses the adrenal artery PI was below the 95% confidence interval. Small-for-gestational-age fetuses with abnormal adrenal artery PI had a significantly higher incidence of fetal heart rate decelerations, preterm delivery and Cesarean sections when compared to small-for-gestational-age fetuses with normal adrenal artery PI. Our data indicate that the PI of the adrenal artery in the normal fetus decreases with advancing gestation, and they suggest that in the small-for-gestational-age fetus there is an increased blood flow to the adrenal gland. We postulate that management of the small-for-gestational-age fetus may be aided by the study of the adrenal artery flow velocity waveforms.

Impact of chronic hypoxemia on blood flow to the brain, heart, and adrenal gland in the late-gestation IUGR sheep fetus

“…These data are consistent with ultrasound studies in humans where blood flow velocity studies suggest that adrenal sparing occurs more often than sparing of brain growth (20). In addition, this finding is in agreement with the observed increase in blood flow to the adrenal gland in the small-for-gestational age human fetus (47). In anesthetized, male rats, ACTH has been shown to increase adrenal blood flow (3); however, we found no difference in plasma ACTH concentrations between the control and PR fetuses, which was consistent with a previous study in this model (67).…”

Can fetal adrenal artery Doppler velocimetry predict delivery date in pregnant women with spontaneous preterm birth?

“…Previous observations have shown vasodilation in the adrenal artery of fetuses with chronic hypoxemia [13][14][15]. These studies describe the presence of vasodilatation in the fetal adrenal artery as being associated with prematurity, higher Cesarean section rates, fetal distress detected by cardiotocography, and longer time periods spent in neonatal intensive care units.…”

“…These authors stated that RI values increased until the 31 st week of gestation and progressively decreased after this age. Fetal adrenal artery Doppler velocimetry showed the ability to differentiate among fetuses with high risks for hypoxemia and those with adverse perinatal outcomes [14,15].…”

Correlation of efficacy of cerebro placental ratio with adverse perinatal outcome in clinically suspected IUGR pregnancies

“…heart, adrenal glands, spleen, brain and kidney), which causes vasodilation of the MCA, with an increase in diastolic flow hence decrease in its PI. [5][6][7][8] Thus, in asymmetrical IUGR, there is a high UAPI and low MCA PI as a result CP ratio is lower than normal in growth retarded fetuses. CP ratio remains constant during last 10 weeks of gestation and so it is having a better diagnostic accuracy.…”