[What does fetal renal echogenicity mean in intrauterine growth retardation?]

The object of this study was to investigate the fetal renal and middle cerebral arterial blood flows in patients with normal and hyperechogenic kidneys during the fetal period.

Study group consisted of 82 pregnancies with intrauterine growth retardation. Group included pregnant women from the third trimester. Hyperechogenic medullae were detected in 17 out of 82 pregnancies with intrauterine growth retardation.

Fetal renal hyperechogenicity appears to be an indicator of fetal arterial circulatory depression, correlated with pathological changes in the pulsatility index for the fetal renal arteries. The fetal renal arterial blood flow pulsatility index was significantly lower in hyperechogenic cases, while in the middle cerebral artery flow was in the normal range. This may also be an indication of subsequent intrauterine and neonatal complications, such as cesarean section because of fetal distress (47%), treatment in a neonatal intensive care unit (71%) or increased perinatal mortality (12%) in our cases.

Detailed ultrasound of renal parenchyma and Doppler examination of renal and middle cerebral arteries appear to be an useful method in the prenatal diagnosis of reduced renal perfusion and of intrauterine hypoxia so as to detect possible pathological fetal conditions in utero.