Usefulness of fetal urine production measurement for prediction of perinatal outcomes in uteroplacental insufficiency.

Abstract

To evaluate whether fetal urine production measurement is useful for predicting adverse outcomes in patients with uteroplacental insufficiency. We enrolled patients with uteroplacental insufficiency at 24 to 40 weeks' gestation and normal pregnancies matched for gestational age and divided them into 3 groups according to perinatal outcomes: group 1 (n = 141), a control group of normal pregnancies; group 2 (n = 29), uteroplacental insufficiency without adverse outcomes; and group 3 (n = 18), uteroplacental insufficiency with adverse outcomes. An adverse outcome was defined as 1 or more of the following: (1) cesarean delivery because of fetal distress; (2) admission to the neonatal intensive care unit; (3) cord arterial pH less than 7.15 at birth; and (4) low 5-minute Apgar score (<7). The fetal urine production rate was obtained by serial bladder volume measurement using virtual organ computer-aided analysis. For bladder volume determination, we scanned the bladder in the 3-dimensional mode and defined the bladder surface contour in the reference plane, repeating the rotation of the reference plane with an angle of 30° and determining the surface contour on each plane. Statistical methods, including the Mann-Whitney U test, Fisher exact test, χ(2) test, and Kruskal-Wallis analysis of variance, were used. Group 3 had a lower mean fetal urine production rate than groups 1 and 2, whereas the urine production rate was not different between groups 1 and 2 (group 1, 49.0 mL/h; group 2, 59.4 mL/h; group 3, 20.7 mL/h; P < .001 between groups 1 and 3 and between groups 2 and 3). This difference between groups 2 and 3 remained significant after adjusting for the amniotic fluid index, umbilical artery Doppler pulsatility index, and presence of fetal growth restriction. Uteroplacental insufficiency cases with adverse perinatal outcomes had a lower fetal urine production rate than those without adverse outcomes. This difference might be used to predict adverse perinatal outcomes in uteroplacental insufficiency.