Bilateral Renal Agenesis

Bilateral Renal Agenesis Definition

Bilateral renal agenesis is uncommon and is a serious condition, related to Potter's Syndrome. Bilateral renal agenesis is the lack of both kidneys at birth. It is a genetic disorder characterized by a failure of the kidneys to develop as a fetus inside the womb. This absence of kidneys results to a deficiency of amniotic fluid (or oligohydramnios) in a pregnant woman. Normally, the amniotic fluid serves as a cushion for the developing fetus. When there is not enough amount of this fluid, compression of the fetus may occur resulting in further malformations of the baby. It is the consequence of failure of differentiation of the metanephric blastema during the 25?28th day of development and both ureters and kidneys and renal arteries are missing. This disorder is more commonly found in infants born of a parent who has a kidney malformation, particularly the absence of one kidney (or unilateral renal agenesis). Studies have proven that unilateral renal agenesis and bilateral renal agenesis are genetically related to eachother. 1 out of 3 infants with this congenital defect are not born alive. Most infants that are born alive do not live beyond the coarse of four hours.

Bilateral Renal Agenesis Diagnosis

Antenatally, the condition is suspected by the combination of anhydramnios (from 17 weeks) and an empty fetal bladder, starting from as early as 14 weeks. Close inspection of the renal areas is often hampered by the oligohydramnios and the ?crumpled' position adopted by affected fetuses, and care should be taken to avoid the mistaken diagnosis of perirenal fat and large fetal adrenals in the place of absent kidneys. The differential diagnosis is from severe uteroplacental insufficiency and obstructive uropathy, preterm rupture of membranes, or bilateral multicystic or polycystic kidneys. Vaginal sonography with high-frequency, high-resolution probes can be utilized in these cases. Failure to visualize the renal arteries with color Doppler is another important factor to the diagnosis in doubtful cases, both with bilateral and unilateral agenesis. Prenatal diagnosis of unilateral renal agenesis can be difficult because there are no major features, such as anhydramnios and empty bladder, to alert the ultrasonographer to the fact that one or both of the kidneys is absent.