P09.03: Measurement of fetal urine production using three‐dimensional ultrasonography rotational technique in normal pregnancy

Abstract

The aim of this study was to measure bladder volume by 3D ultrasonography to establish a correlation between urine production rate (UPR) with amniotic fluid index (AFI) and peak sistolic velocity (PSV) of the renal artery. We collected 121 cases of normal singleton pregnancy without medical or obstetric complications. The gestational age was between 20 and 38 weeks. The method to obtain volume measurement from 3D volume datasets was VOCAL (virtual organ computer-aided analysis, GE Medical System, Zipf, Austria). To calculate the rate of fetal urine production, we measured bladder volume at intervals of 5 mins following this formula: urinary production rate (UPR) (mL/h) = (second bladder volume – first bladder volume) x (60/x) where x is the time interval in mins between bladder volume measurements. For each case we considered also 2D ultrasonography to evaluate fetal biometry, AFI, Doppler measurements (resistance index, PSV of renal artery). The mean of UPR rate was 3.53 ml/h in according with the data of literature. Considering the Doppler measurements taken for each patient of our study we demonstrated the correlation between UPR and both RI and PSV of renal artery (p < 0.05). We couldn't find out a significative relation between UPR and AFI (p = 0.750). Measurement of fetal urine production may therefore be an alternative to AFI or single deepest pocket, and might provide an alternative to amniotic fluid volume measurement as a means of evaluating fetal hypoxia. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.