Definition, diagnosis and management of fetal lower urinary tract obstruction: consensus of the ERKNet CAKUT-Obstructive Uropathy Work Group

Abstract

Fetal lower urinary tract obstruction (LUTO) is associated with high mortality and postnatal morbidity caused by lung hypoplasia and impaired kidney function. Specific diagnostic features that can guide clinical approach and decisions are lacking; thus, the European Reference Network for Rare Kidney Diseases established a work group to develop recommendations regarding the clinical definition, diagnosis and management of prenatally detected LUTO. The work group recommends the use of antero-posterior diameter of renal pelvis as the most reliable parameter for suspecting obstructive uropathies and for suspecting prenatal LUTO in the presence of fetal megacystis. Regarding prenatal and postnatal prognosis of fetuses with LUTO, the risk of fetal and neonatal death depends on the presence of oligohydramnios or anhydramnios before 20 weeks' gestation, whereas the risk of kidney replacement therapy cannot be reliably foreseen before birth. Parents of fetuses with LUTO must be referred to a tertiary obstetric centre with multidisciplinary expertise in prenatal and postnatal management of obstructive uropathies, and vesico-amniotic shunt placement should be offered in selected instances, as it increases perinatal survival of fetuses with LUTO.

Posterior urethral valves: Role of prenatal diagnosis and long-term management of bladder function; a single center point of view and review of literature

“…Posterior urethral valves (PUV) are the most common cause of bladder outlet obstruction (BOO) in the pediatric population and are considered to be one of the life-threatening neonatal congenital pathologies. It leads to chronic kidney disease during childhood and adolescence in up to 32% of patients (1)(2)(3).…”

Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations

“…In this consensus statement, we focus on kidney dysplasia without obstruction. Relevant aspects of obstructive nephropathy have been addressed by an independent ERKNet project [ 8 ]. We focus on the clinically most relevant cohort of patients with bilateral disease, which has the highest risk for CKF.…”

Management of very young fetuses with LUTO

“…In this manuscript, the authors make some observations based on previous studies: a bladder diameter ≥15 mm in the first trimester of pregnancy suggests severe LUTO with little chance of spontaneous resolution 2 ; the presence of anhydramnios early in the second trimester of pregnancy results in a fetal mortality rate close to 100%, and untreated fetal LUTO with an early onset (first or early second trimester of pregnancy) can lead to death in up to 80% of fetuses [1][2][3][4] ; and a small window of opportunity for improved renal outcomes and survival exists (<6 weeks), as renal function gets lost progressively in fetuses with severe LUTO 5 .…”

“…However, the new guidelines 1 about LUTO management primarily focus on mid-gestation fetuses and provide no recommendations about how to best handle this early-gestation subgroup of fetuses with LUTO. Thus, the staging system that the authors propose as well as some of the European Reference Network for Rare Kidney Diseases (ERKNet) recommendations for prenatal definition, diagnosis and management of LUTO 1,6 do not fit the needs of the youngest and most severely affected fetuses.…”

“…The purpose of this Correspondence is, therefore, to raise awareness about the availability of intervention methods alternative that this information needs to accompany the novel management guidelines for fetal LUTO 1 .…”