Assessment Of Fetal Urine Production Rate By Three-dimensional Ultrasonography Using VOCAL During Normal Human Gestation And In Fetuses With Congenital Heart Disease And Hydronephrosis

Objective To measure fetal bladder volume using the virtual organ computer- aided analysis (VOCAL) technique ,and to establish a normal fetal urine production rate (UPR) according to gestational age (GA).Methods⑴30 women with normal singleton pregnancy were selected for the reproducibility. Fetal bladder volume was measured by both two-dimensional ultrasound (2DUS) and three-dimensional ultrasound (3DUS). The formula V=0.5×L×H×W was used by 2DUS,whereas VOCAL technique by 3DUS;⑵314 women with normal singleton pregnancy at 21 to 40 weeks'gestation were selected in this study. Fetal bladder volume was measured two or three times every 5～15minutes and UPR was calculated from serial measurements using virtual organ computer-aided analysis (VOCAL) by three-dimensional ultrasound. The mean value of calculated UPRs were plotted against GA to establish the nomogram with linear regression.Results⑴A higher degree of reproducibility was observed in measurement of fetal bladder volume by 3DUS than by 2DUS, the intraclass correlation coefficient (ICC) of intraobserver and interobserver were 0.942 vs. 0.879 and 0.967 vs. 0.865;⑵Fetal UPR increased with gestation age (GA) at 21～40 weeks'gestation. It increased from a mean value of 4.48ml/h at 21 weeks'gestation to 66.54 ml/h at 40 weeks'. There was a significant correlation between the fetal UPR and GA.The regression formula is: Ln(UPR) = - 4.748 + (0.398×GA)+(-0.004×GA~2 ) ,r~2=0.916,P<0.05.⑶Fetal UPR was not associated with AFI.(r=0.071) Conclusion⑴A higher degree of reproducibility was observed in measurement of fetal bladder volume by 3DUS than by 2DUS;⑵Fetal UPR can be easily measured by VOCAL for assessment of fetal bladder volume. Objective To evaluate the change of UPR of fetuses with congenital heart disease(CHD) and hydronephrosis(HN).Methods 314 women with normal singleton pregnancy at 21 to 40 weeks'gestation were selected as the control group, and 49 consecutive fetuses with CHD and 58 consecutive fetuses with HN in the same period were selected as the case group. The group of CHD was divided into three types according to Kaltman's classification: left-sided obstructive lesions (10 cases), right-sided obstructive lesions (11 cases) and mixed type of CHD (28 cases). Then CHDs were further divided into two types: CHD complicating congenital heart failure (CHF) (11 cases) and CHD without CHF (38 cases). According to the classification from the Society for Fetal Urology: Grade 0, normal echogenic renal complex; Grade 1, dilated renal pelvis splitting central renal complex; Grade 2, dilated renal pelvis confined to the sinus and no dilated calyces; Grade 3, renal pelvis dilated beyond the sinus and dilated calyces with no parenchymal thinning; Grade 4, dilated renal pelvis and calyces as well as parenchymal thinning (1/2 of normal side), the group of HN was classified into mild group (Grade 1 and Grade 2 ,21 cases ), moderate group (Grade 3 ,15 cases) and severe group (Grade 4 ,22 cases). Fetal UPR was measured by three-dimensional ultrasound using virtual organ computer-aided analysis (VOCAL). Results⑴Fetal UPR was not associated with CHD and its types (P>0.05);⑵Heart function played a role on the fetal UPR. Fetal UPR decreased when CHD complicating CHF (P<0.01);⑶HN has an impact on fetal UPR. Fetal UPR decreased in fetuses with severe HN (P<0.01).Conclusion Fetal UPR can be easily measured by three-dimensional ultrasound using VOCAL. UPR may be a valuable indicator to evaluate fetal CHF and renal function.