Fetal Kidney Problem – Everything You Want To Know

Are you pregnant and worrying about your unborn baby’s health? Has your doctor spoken to you about various issues with unborn babies? Problems related to kidneys are one of the common issues that affect the fetus. The kidneys of the fetus start to develop from the very beginning of the pregnancy, during the first month itself. The kidneys produce urine and maintain normal levels of electrolytes and fluids in the body. The major part of the amniotic fluid also consists of fetal urine produced by fetal kidneys. Issues with the development of kidneys during the fetal growth can result in renal complications after the birth of the baby. Proper monitoring and medical intervention can reduce the risk of these complications. Continue reading to know more about fetal kidney problem, its causes and various treatment options.

What Are The Different Types Of Fetal Kidney Problems?

The main types of fetal kidney problems are:

1. Hydronephrosis: Hydronephrosis is an enlargement of the kidney, particularly the funnel-like part where urine is stored after its production. The dilation can be with or without obstruction or block.The dilatation without block can be due to the following reasons:
   • The fetal kidney is not able to concentrate the urine. As a result, the volume of the urine that flows out and stored will be very high, making it dilated
   • The stretchy and immature urethral tissues

   The dilation with obstruction can be either unilateral (one kidney) or bilateral (both kidneys). The most commonly found obstructions are:

   • Posterior urethral valves: It is a fairly common defect found in male child. It occurs due to growth of additional flaps of tissues that develop in the urethra and block the normal urine flow as a result the urine is accumulated from the bladder and all the way up to the ureter. This can lead to organ damage such as the bladder and kidneys
   • Ureteropelvic junction obstruction (UPJ): Ureteropelvic junction (UPJ) obstruction occurs at the junction where the ureter attaches to the kidney. As a result of this, there is decrease in the flow of urine down the ureter which leads to an increase in pressure of fluid inside the kidney. Increased pressure in the kidney can damage kidney function
   • Ureterovesical junction obstruction (UVJ): Ureterovesical obstruction (UVJ) is not as common as UPJ obstruction. Here the blockage occurs due to the defect in attaching the ureter into the bladder, obstructing the flow of the urine into the bladder
   • Ureterocele: Ureterocele is a deformation in the part where a ureter, the tube from the kidney, enters the bladder. It is in the shape of a balloon and can cause problems like obstruction in the normal flow of urine from the kidney. This results in accumulation of urine in ureter and kidney. If this blockage is not rectified then it can result in the kidney to lose its capability to purify blood and urine and can also cause infections after birth which can be dangerous for the baby
   • Neurogenic bladder: Neurogenic bladder refers to issues of the bladder caused due to nerve damage. Usually, the urinary system muscles and nerves work jointly for holding urine in the bladder and releasing it at the right time. Nerves transmit messages from the bladder to the brain and from the brain to the muscles of the bladder. These messages guide the bladder muscles either to contract or relax. But in case of a neurogenic bladder, there is a malfunction in the nerves which carry these messages due to various reasons. This has a paralyzing impact on the bladder. If the obstruction is unilateral, affecting one kidney and the contralateral kidney is good and healthy, then there is not a problem with kidney function as the single kidney increases its function and capacity and can perform 90% of the function that two normal kidneys would have done and the baby will be fine. However, if the obstruction is bilateral, it will be a more complicated and severe issue
2. Polycystic Kidney Disease: Polycystic kidney disease (PKD) is a hereditary issue which results in the growth of numerous fluid filled cysts in the kidneys. As they grow, the cysts can damage the kidney tissues. Polycystic kidney disease happens because of genetic mutations
3. Fetal Multicystic Dysplastic Kidney: It is a disorder that occurs due to deformity of the kidney during the development of the fetus. In this condition, grape like cysts start developing in the unborn baby’s kidneys

What Causes Kidney Problems In Unborn Babies?

Doctors are not yet sure about the main cause of fetal kidney problems. This is a very rare condition. However, as explained above: