Assessment of renal volume by 3D VOCAL Ultrasonography method in late-onset growth-restricted fetuses with normal amniotic fluid index

Objectives: The aim of this study was to study renal volumetric alterations and renal artery doppler changes in late-onsetfetal growth restricted (FGR) fetuses with normal amniotic fluid compared to healthy pregnancies.Material and methods: This prospective study was composed of pregnant women with late-onset FGR and a control groupof uncomplicated pregnancies within 32–37 weeks of gestation. Following the assessment of umbilical, bilateral uterine,middle cerebral using Doppler Ultrasonography (US), three dimensional (3D) US Virtual Organ Computer-aided Analysis(VOCAL) was executed to calculate bilateral renal volumes.Results: A total of 76 fetuses with FGR and 51 healthy fetuses (control group) were evaluated. Umbilical artery Dopplersystole/diastole and Pulsatility index values were found to be significantly different between the two groups (p = 0.001 andp = 0.001, respectively). Middle cerebral, bilateral uterine, and bilateral renal arteries’ Doppler indices revealed no differencebetween the two groups. Right, left, and mean renal volume of the fetuses with FGR were smaller than the controlgroup, and the differences were statistically significant (p = 0.025, p = 0.004, p = 0.004, respectively). Left renal volume wassignificantly greater than the right renal volume in the control group (p = 0.009).Conclusion: Although not accompanied by oligohydramnios, and having similar renal vascular resistance as the controlgroup, renal volumes of fetuses with late-onset FGR were still observed lower than the control group. This difference wasexplained by not decreased blood flow via redistribution but other mechanisms like glomeruli reduction and glomerularapoptosis