Causes Of Bilateral Renal Agenesis: Symptoms And Survival

Bilateral renal agenesis is a rare congenital condition in which both the kidney are absent in the fetus. It is an uncommon condition. According to an estimate bilateral renal agenesis occurs in one out of ten thousand pregnancies. The most striking sign and symptom of this condition is reduced amount of amniotic fluid in the pregnant woman and absence of urinary bladder and both the kidneys in the fetus.

Amniotic fluid is built up in the amniotic sac covering the fetus. Presence of fluid provides adequate cushion for the baby during its movement.

With insufficient fluid the fetus may get compressed and the lungs may not fully develop. This makes it very difficult for the fetus to survive after birth. At least 50 percent of fetuses are stillborn and the rest die shortly after birth. Bilateral renal agenesis cannot be treated or managed.

What Causes Bilateral Renal Agenesis?

The exact cause of bilateral renal agenesis is yet not determined by researchers. However, it is presumed to be caused due to mutation of genes. Normally kidneys bud in fetus as early as 12 weeks of gestation. It is on the posterior side of abdomen.

But in agenesis the kidney does not develop during the growth of fetus.

There are certain factors that increase the risk of bilateral renal agenesis; parent having malformed kidney or only one kidney increases the risk of bilateral renal agenesis in their babies. It is one of the prominent risks. Risk of bilateral renal agenesis is more in male fetus as compared to female.

Other factors that increase the risk of this condition are mother suffering from diabetes or gestational diabetes, pregnancy at young age, alcohol abuse, drug abuse.

Symptoms Of Bilateral Renal Agenesis

Bilateral renal agenesis has many characteristic features. Deficiency of amniotic fluid in pregnant woman increases the possibility of bilateral renal agenesis. Along with reduced amniotic fluid, there is absence of urinary bladder and both the kidneys in the developing fetus.

The condition is sporadic. Only one out of ten thousand pregnancies may have bilateral renal agenesis. New born with this condition may have low set ears, wide set eyes, nose like parrot beak, receding chin, dehydrated skin, prominent fold in the inner side of the eye, defect in limbs. The mentioned facial features are called as Potter’s facies.

Bilateral Renal Agenesis Diagnosis And Survival

Bilateral renal agenesis is identified during the routine sonography of pelvis that is carried out during the first trimester and second trimester of pregnancy. The suspicion of bilateral renal agenesis increases when there is reduced amniotic fluid detected on ultrasound. The kidneys are absent in renal fossa. There are associated underdeveloped lungs. All the three together are strong indicative diagnosis of bilateral renal agenesis.

Bilateral renal agenesis is not treatable condition. It is lethal condition. The fetus may die within few hours after birth due to pulmonary hypoplasia or may be stillborn.

Bilateral renal agenesis cannot be prevented as it caused due to genetic mutation. The mother must stop intake of alcohol during pregnancy. Parents must be counseled for the risk factors if they have previous history of fetuses having bilateral renal agenesis or if they have single kidney.

Absence of both kidneys since birth has very poor prognosis. The neonate dies few hours after birth.