Prenatal Diagnosis of Anterior Urethral Valve: A Case Report

Anterior urethral valves are a rare cause of lower urinary tract obstruction (LUTO) in the fetus. Prenatal diagnosis is primarily based on ultrasound imaging, and the condition can lead to progressive renal dysfunction and pulmonary hypoplasia secondary to oligohydramnios. Therapeutic management remains complex and lacks consensus. We present the case of a male fetus in a 36-year-old primigravida who was referred at 16 weeks and 6 days of gestation for fetal megacystis. Morphological ultrasound revealed dilatation of the distal penile urethra, as well as megacystis and bilateral pelvicalyceal dilatation. These findings could indicate an anterior urethral valve. Two vesicocenteses were performed in succession, which revealed impaired fetal renal function with unfavorable biochemical markers. The progression to oligohydramnios and a poorly filled bladder confirmed a poor prognosis. After receiving counsel from a variety of specialists, the parents decided to proceed with the termination of the pregnancy. This procedure was performed at 19 weeks and 4 days of gestation. Although rare, an anterior urethral valve should be considered in the differential diagnosis of fetal LUTO. Prognosis depends on the timing of obstruction onset, the severity of renal involvement, and the early detection of sonographic signs. The combination of fetal imaging, urinary biomarkers, and prognostic scoring systems can aid clinical decision-making. However, further studies are needed to better define the indications for prenatal interventions and their impact on postnatal survival and quality of life.