Blood flow velocity waveforms of the abdominal arteries in appropriate‐ and small‐for‐gestational‐age fetuses

Abstract

The aim of this study was to describe flow velocity waveforms of abdominal arteries in the appropriate- and small-for-gestational-age fetus. Splenic artery, superior mesenteric artery, hepatic artery and renal artery velocity waveforms were obtained from 57 appropriate-for-gestational-age and nine small-for-gestational-age fetuses with color flow Doppler ultrasonography. The pulsatility index was used to quantify the arterial waveforms. Repeated measure analysis of variance indicated significant differences in the pulsatility index values in both the appropriate-for-gestational-age and small-for-gestational-age fetuses. A multiple comparison test revealed a significantly lower value for the pulsatility index in the splenic artery when compared to that of the other vessels for both the appropriate- and small-for-gestational-age fetuses. In the small-for-gestational-age fetuses, a lower pulsatility index value was observed at the superior mesenteric artery level when compared to the renal artery. Because of its lower frequency of successful insonation, the hepatic artery was not considered for the analysis. In the normal fetus, the splenic artery had the lowest pulsatility index when compared to the other arteries we investigated. This difference remained in small-for-gestational-age fetuses, reflecting a lower vascular resistance at the fetal spleen in both normal and small-for-gestational-age fetuses. It appears that in small-for-gestational-age fetuses the renal artery has a higher pulsatility index than the superior mesenteric artery, suggesting a preferential distribution of blood flow to the bowel.

Nonobstructive Dilatation of the Fetal Bowel in Twin Gestations

“…Although the sparing effect of the splenic, adrenal, coronary and cerebral arteries has been reported in response to chronic fetal hypoxia [19][20][21], the sparing effect of splanchic circulation has rarely been described. Mari et al [22] showed a decreased PI in the abdominal arteries of SGA fetuses, compared with AGA control fetuses. Recently, compensatory elevated blood flow in the hepatic artery of SGA fetuses was reported [23].…”

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.…”

“…The only reference range of the fetal mean adrenal artery PI was described by Mari et al [15]. They assessed 131 singleton pregnancies and observed that PI values decreased with increasing gestational age.…”

“…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].…”

The role of venous Doppler studies in the monitoring of growth-restricted fetuses

“…Fetuses that show these early Doppler changes are at increased risk for hypoxemia, while the pH is usually maintained in the normal range [27]. Concurrently blood flow resistance in peripheral pulmonary arteries [28], celiac axis [29], mesenteric vessels [30], renal [31], femoral and iliac arteries [32] may be elevated. Individual vital organs such as the adrenal glands [33] and spleen [34] may show evidence of enhanced blood flow.…”