Fetal Lower Urinary Tract Obstruction (LUTO): a practical review for providers

Abstract

Fetal lower urinary tract obstruction (LUTO) is a serious condition, which commonly results in marked perinatal morbidity and mortality. The characteristic prenatal presentation of LUTO includes an enlarged bladder with bilateral obstructive uropathy. While mild forms of the disease result in minimal clinical sequelae, the more severe forms commonly lead to oligohydramnios, dysplastic changes in the fetal kidneys, and ultimately result in secondary pulmonary hypoplasia. The aim of this review is to provide practitioners with a practical and concise overview of the presentation, evaluation, and treatment of LUTO.

Fig. 1

Ultrasound image of fetal bladder obstruction with the characteristic “keyhole” sign (B: Bladder, u: urethra)

Fig. 2

Ultrasound image of hyperechoic and small for gestational age fetal kidneys, secondary to fetal lower urinary tract obstruction

Fig. 3

Ultrasound image of a vesicoamniotic shunt with the two catheter ends (S) in the fetal bladder (B) and amniotic cavity (A)

Fig. 4

Fetal cystoscopy image within the bladder (B) demonstrating the point of obstruction at the urethra (U)

Fig. 5

a pre-amnioinfusion insertion of an echo-tip 22 gauge needle into the amniotic cavity (pocket of loops of cord adjacent to fetal limb), and b) Color Doppler imaging demonstrating amnioinfusion using sterile saline