Assessment of renal circulation in small for gestational age and appropriate for gestational age term newborns: A prospective study

Abstract

To compare selected parameters of renal circulation between small for gestational age (SGA) and appropriate for gestational age (AGA) newborns. Fifty-two SGA and 100 AGA term newborns were examined. The size of the kidneys were measured, and renal blood flow in the central and intraparenchymal renal arteries were assessed via Doppler sonography. Peak systolic velocity (PSV), end diastolic velocity (EDV), mean blood flow velocity (V mean), resistance index (RI), and pulsatility index (PI) were determined and compared between the groups. No statistically significant differences in the velocity parameters were found between SGA and AGA infants in central renal arteries. Slightly higher RIs and PIs were seen in AGA newborns (RI, 0.76 +/- 0.13 versus 0.78 +/- 0.06 [p < 0.05]; PI, 1.65 +/- 0.54 versus 1.84 +/- 0.46 [p < 0.05]). There were statistically significant differences between the groups in all measured parameters in intraparenchymal arteries (RI, 0.57 +/- 0.11 versus 0.63 +/- 0.05 [p < 0.001]; PI, 0.89 +/- 0.26 versus 1.09 +/- 0.16 [p < 0.001]) except PSV (7.11 +/- 1.55 versus 7.14 +/- 0.81 cm/s [p > 0.05]). Based on our findings, we suggest that renal circulation is not negatively influenced by intrauterine growth restriction in SGA neonates compared with AGA newborns.