The effect of fetal congenital heart disease on in utero urine production rate.

OBJECTIVES

To evaluate the influence of congenital heart disease (CHD) or congestive heart failure (CHF) on fetal urine production rate (UPR) and to establish normal reference intervals.

METHODS

A cross-sectional study was performed on normal fetuses (n = 314) and on fetuses with CHD (n = 49). CHD cases were divided into groups on the basis of heart function as defined by Huhta score: with CHF (n = 11) and without CHF (n = 38). Fetal bladder volume was measured by two-dimensional as well as three-dimensional ultrasound with the Virtual Organ Computer-aided Analysis technique.

RESULTS

In normal fetuses, UPR increased with gestational age from a mean value of 4.5 mL/h at 21 weeks to 66.5 mL/h at 40 weeks. There were no significant differences in UPR between CHD cases without CHF and controls (P = 0.581). However, fetuses with CHF had decreased UPR values (Controls vs. CHF, P = 0.007) compared with the controls. The interobserver and intraobserver variability for assessment of UPR was better using three-dimensional rather than two-dimensional US.

CONCLUSIONS

Fetal UPR can be reproducibly measured by the Virtual Organ Computer-aided Analysis technique. It appears that heart function, rather than CHD, affects fetal UPR. Fetal UPR may therefore be an additional indicator of CHF.