unilateral renal agenesis

diagnosis

unilateral renal agenesis should be suspected when a single umbilical artery is found. a unilateral cystic or dysplastic kidney together with oligohydramnios should raise the suspicion of ura on the contralateral side. a family history of renal malformations should also raise the suspicion for ura and ura is seen in 4.5% of first degree relatives affected with bilateral renal agenesis. the diagnosis is made by seeing only one kidney. it is important to search for a second kidney in an ectopic location including the pelvis and rarely even the thorax. normal fetal bladder filling and normal amniotic fluid volume is usually seen unless the single kidney is abnormal. associated findings include single umbilical artery, genital abnormalities (females, 25 to 50%, males, 10 to 15%). in males there is a high incidence of absent or malformed proximal mesonephric duct structures (including vas deferens, seminal vesicle and ejaculatory duct). there are absent or malformed mullerian duct structures (uterus and fallopian tube) in the female. other organ system abnormalities including cardiovascular (30%) gastrointestinal (25%) and 2022年世界杯预选赛规则图解 (14%).