What is biparietal diameter/kidney length ratio in cases with renal hyperechogenicity?

The object of this study was to investigate the fetal biparietal diameter/kidney length ratio in normal and hyperechogenic kidneys during the 3rd trimester of gestation. Screened pregnancies were chronically hypoxic [i.e. intrauterine growth retardation (IUGR)]. Depending on the renal manifestation of the intrauterine chronic hypoxia, the cases were divided into two study groups. Group I was composed of 28 fetuses with IUGR and hyperechogenic renal medullae. Group II consisted of 62 fetuses with IUGR and normal echoic kidney. Both study groups included pregnant women from the 3rd trimester. Fetal renal hyperechogenicity is an indicator of depression of fetal renal perfusion, correlated with pathological growth in the fetal kidney development. The fetal biparietal diameter/kidney length ratio was significantly higher in hyperechogenic cases. This may also be an in utero indicator of subsequent intrauterine and neonatal complications. Detailed ultrasound examinations of renal parenchyma and length appear to be useful in the prenatal diagnosis of reduced renal perfusion and of intrauterine hypoxia, allowing detection of possible pathological fetal conditions in utero.