Fetal bladder morphology as a predictor of outcome in fetal lower urinary tract obstruction

Abstract

ObjectiveWe evaluate survival of fetuses with severe Lower Urinary Tract Obstruction (LUTO) based on bladder morphology. We hypothesize that fetuses with a “floppy” appearing bladder on initial prenatal ultrasound will have worse infant outcomes than fetuses with full/rounded bladders.MethodWe retrospectively reviewed all cases of LUTO evaluated in our fetal center between January 2013 and December 2021. Ultrasonographic assessment, renal biochemistry, and bladder refilling contributed to a “favorable” or “unfavorable” evaluation. Bladder morphology on initial ultrasound was classified as “floppy” or “full/rounded.” Vesicoamniotic shunting was offered for favorably evaluated fetuses. Baseline demographics, ultrasound parameters, prenatal evaluations of fetal renal function, and infant outcomes were collected. Fetuses diagnosed with severe LUTO were included in analysis using descriptive statistics. The primary outcome measured was survival at 6 months of life.Results104 LUTO patients were evaluated; 24 were included in analysis. Infant survival rate at 6 months was 60% for rounded bladders and 0% for floppy bladders (p = 0.003). Bladder refill adequacy was lower in fetuses with floppy bladders compared with rounded bladders (p value < 0.00001).ConclusionWe propose that bladder morphology in fetuses with severe LUTO may be a prognostication factor for predicting infant outcomes and provides a valuable, noninvasive assessment tool.

Twenty years of progress in the diagnosis and management of foetal urinary tract conditions

“…We do include some studies describing sonographic features that may help predict prognosis in foetuses with lower urinary tract obstruction. [1][2][3] Nowadays large cohort studies and systematic reviews are forthcoming that bring to light which types of renal tract anomalies are most commonly associated with chromosomal copy number variants and which associate with monogenic conditions. 4 Thus, foetal renal phenotype is informing genetic testing strategies as we begin to connect genotype to foetal phenotype, and to develop more universal standard descriptions to categorize our sonographically identified renal anomalies for better clinical application.…”