ABSTRACT
Renal agenesis is a disorder characterized by the congenital absence of one or both kidneys due to complete failure of the kidney to form. The syndrome of renal agenesis is severe oligohydramnios, amnion nodosum, flattened face, low-set and floppy ears, and bilateral pulmonary hypoplasia. Bilateral renal agenesis occurs in 0.1 to 0.3 per 1000 births and unilateral involvement occurs in 1 in 500 to 1 in 1300 live births.1,2 Bilateral renal agenesis is an invariably lethal condition, and is associated in more than half of the affected individuals with malformations of the genitourinary tract, cardiovascular system, vertebral bodies or imperforated anus.2 Accurate diagnosis in the mid-trimester permits the parents to allow elective termination. However, the nearly absent amniotic fluid makes an accurate assessment of fetal kidney difficult. We present a case of unilateral renal agenesis with contralateral renal hypoplasia, diagnosed by ultrasonography after amnioinfusion at 21 weeks gestation.