Prenatal sonographic features and outcome of in utero resolution of the anterior urethral valve in one of the twin

Anterior urethral valve is a rare cause of lower urinary tract obstruction, and its prenatal diagnosis rate is low. We reported intrauterine remission of the anterior urethral valve in one of the twin. Comprehensive urinary tract dilatation was detected at the 18th week. Subsequently, spontaneous rupture of the anterior urethral valves was observed in the 20th week, alleviating urethral dilatation. Therefore, the dilatation of the urinary system in fetuses with prenatal urinary tract obstruction may be relieved with gestational age, and close observation and follow-up are needed until postpartum.