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Baby Kidney Problems in Pregnancy: Expert analysis!

Baby Kidney Problems in Pregnancy: Expert analysis!

There are different types of baby kidney problems in pregnancy such as:

  • Fetal Hydronephrosis.
  • Kidney Dysplasia.
  • Autosomal Recessive Polycystic Kidney Disease.
  • Ectopic Kidney.
  • Renal Agenesis.
    • Unilateral Renal Agenesis.
    • Bilateral Renal Agenesis.

In this blog, we’ll discuss the different baby kidney problems in pregnancy, their causes and treatments in detail.

Pregnancy is an exhilarating experience in the life of every woman. Right from the beginning, expecting mothers start thinking about different things related to infants. They focus on everything needed for the proper growth of the fetus. They keep checking on the foods that are harmful or beneficial for the growth of the unborn baby. Check on other aspects is also carried out.

What are baby kidney problems in pregnancy?

Kidneys are one of the most important organs of the human body. Kidneys performs following important functions:

  • They remove toxic materials from the body by producing urine.
  • Kidneys regulate levels of electrolytes in body.
  • They maintain minerals in the body.
  • They produce red blood cells and control blood pressure levels too.

In the case of unborn babies, the kidneys start to develop during the first month of conception. Therefore, they are among the first organs to be developed. However, there are always chances that different types of anomalies can occur in the kidneys of the fetus. Genes are responsible in most cases for kidney anomalies. The good news is that early detection (through ultrasound) helps in timely treatment of such kidney problems.

Let’s discuss different baby kidney problems in pregnancy in detail:

1. Fetal Hydronephrosis

Human urinary functions need to be understood for understanding this kidney problem. Kidneys perform the task of filtering the human blood. Urine takes out all the waste products of this filtration process. The pelvis or basin of the kidneys collects the urine. Urine then goes through the ureter to the urinary bladder. Finally, urine goes out of the bladder through the urethra and out of the body.

Fifth week of gestation is the time when the kidneys of the unborn babies start producing urine. This urine increases the amount of amniotic fluid surrounding the fetus. If the kidneys work properly, the amount of amniotic fluid remains adequate. There are many benefits of an adequate amount of amniotic fluid for the unborn babies.

In hydronephrosis, the urine of the unborn infant keeps on accumulating in the pelvis of the kidneys. As a result, one or both kidneys of the baby start to swell. Mostly, a blockage occurs in the ureter. This does not allow urine to go through its normal passage easily. Severity of hydronephrosis depends on how large the kidney/s have become.

What are the causes of fetal hydronephrosis?

Parents are usually concerned about causes of enlarged kidney in fetus boy or girl. Some major causes of hydronephrosis are as follows:

  • A blockage may occur at any point or part of the entire urinary tract.
  • Sometimes, the fetus may develop an extra ureter that hinders the movement of urine from the kidneys to the bladder.
  • Any other birth defect related to kidneys may occur, leading to hydronephrosis as well.
  • Sometimes, the urine starts a reflux movement (a backward movement) and this causes hydronephrosis.
  • Kidneys may also develop immaturely causing more stress on the pelvis.

How fetal hydronephrosis is diagnosed?

Ultrasound is the best approach for diagnosing fetal hydronephrosis. Gestation age of 20 to 24 weeks is the ideal time for detecting fetal hydronephrosis. Doctors can check the developing urinary tract of the fetus easily through ultrasound. An ultrasound can show:

  • How each kidney looks like.
  • What is the dilatation amount of the kidney’s pelvis.
  • Which kidney is affected.
  • What is the amount of the amniotic fluid.
  • What is the size and thickness of the fetal bladder.
  • The accuracy of the emptying functions of the fetal bladder.
baby kidney problems in pregnancy
Ultrasounds are the best options to check for fetal anomalies!

Once these parameters are obtained, the doctors decide the level of hydronephrosis in the fetus. If the enlargement of the pelvis goes beyond 10 mm, then there is a diagnosis of severe hydronephrosis. If the enlargement is between 4 and 10 mm, then there is a diagnosis of mild hydronephrosis.

Sometimes the pelvis is enlarged. However, the size is not big enough for diagnosing hydronephrosis. In such cases, doctors diagnose the condition as fetal pyelectasis. There is another name for this condition i.e. renal pelvic dilatation.

What is the treatment for fetal hydronephrosis?

For fetal pyelectasis:

  • 90% of the cases are solved on their own while the baby is in the mother’s womb.
  • About 10% of cases move towards hydronephrosis.

For fetal hydronephrosis:

Mothers having unborn babies with hydronephrosis need to consult specific specialist doctors of the field, for instance:

  • 15% of mild fetal hydronephrosis cures on its own.
  • 85% of mild fetal hydronephrosis leads towards abnormal urinary tracts in babies.
    • Of these 85% cases, only 10% or 15% babies need surgeries in after birth.
  • Gynecologists who are expert in handling high-risk pregnancies.
  • Urologists who specialize in urinary tract diseases.
  • Nephrologists who deal with human kidneys.
  • Neonatologists who specialize in treating newborn babies.

After the baby is born, he or she will be kept in the nursery for observation. Several ultrasounds are carried out to check the development of kidneys. If things appear normal, baby is discharged. If things worsen, surgery is the option. However such surgeries are never done right after delivery. Some time is needed so that newborn can develop.

2. Kidney Dysplasia

Kidney dysplasia is an abnormality of the internal structures of fetal kidneys. In normal development, tubules grow into a network of branches. These tubules are responsible for collecting and passing the urine from the kidney. However, these tubules fail to form branches in kidney dysplasia. As a result, the urine also fails to pass out.

The urine starts accumulating inside the kidneys. This leads to formation of sacs called cysts inside the kidneys. These cysts start replacing the normal tissues of the kidneys. That is why this disease is also called multicystic dysplastic kidney disease and renal dysplasia as well.

What are the causes of kidney dysplasia?

Following are the major causes of kidney dysplasia in unborn babies:

  • Genes that the fetus inherits from the parents are primarily responsible for the onset of kidney dysplasia. Such genes can be mutated or altered in nature.
  • Genetic syndromes can also cause kidney dysplasia as part of a combined bodily situation.
  • Last but not least, certain medications used by pregnant mums also cause kidney dysplasia.
  • Drug abuse such as cocaine by pregnant mums also leads to kidney dysplasia.

How kidney dysplasia is diagnosed?

Kidney dysplasia is a birth defect that occurs during pregnancy. That is why, fetal sonograms or ultrasounds are the best way to check for this disease in unborn babies. This technique uses a harmless way of sound waves to create images of the internal structures of the fetus within mother’s womb.

What is the treatment for kidney dysplasia?

  • If both kidneys of the fetus suffer from kidney dysplasia, such fetuses seldom survive. Most of them do not survive and die.
  • Even if such babies survive, they require;
    • Transplantation of kidney.
    • Dialysis.
  • If one kidney is affected and other is normal, then such babies do not require dialysis or transplants for several years in the future. However, still certain regular checkups are necessary for such babies:
    • Regular blood pressure checkup.
    • Regular urine testing, especially for albumin as it is a sign of kidney malfunctioning.
    • Timely ultrasounds to check kidneys.
    • Regular blood tests.

3. Autosomal Recessive Polycystic Kidney Disease

Fluid-filled cysts are formed in the kidney of fetuses in this rare genetic disorder. Because of this, the kidneys enlarge in size. ARPKD causes problems in breathing. This occurs because the amount of amniotic fluid decreases. This is why fetuses usually do not survive. Even if the baby survives, a life-long treatment plan is usually needed. However since it is an autosomal recessive disease, very few fetuses suffer from it.

What are the causes of autosomal recessive polycystic kidney disease?

As its name indicates, ARPKD is an autosomal recessive disease. This means that genes are exclusively involved in this disease. However it is also essential that both the parents pass the mutated gene to the fetus. Only then will this disease occur. If only one parent will provide the gene, then the child will simply become a carrier of ARPKD. He’ll be likely transmit this disease in the next generation.

How ARPKD is diagnosed?

Again like every prenatal disease of unborn babies, ultrasound imaging or sonogram images give a diagnosis of ARPKD. Based on these diagnostic images, further medical care is provided. This is one of the major baby kidney problems in pregnancy.

baby kidney problems in pregnancy
Ultrasounds are the safest way to diagnose kidney problems in fetuses!

What is the treatment for ARPKD?

  • Doctors always go for removing the enlarged kidneys because they cannot be cured.
  • Physicians choose dialysis and kidney transplants in certain cases.
  • Doctors also choose artificial ventilation to treat breathing problems associated with ARPKD.
  • Similarly, doctors use nutritional guidelines to treat growth failures in babies having ARPKD.

4. Ectopic Kidney

Normally, the human kidneys are located near the middle of the back. This position is right below the human rib cage. In ectopic kidneys, this positioning is different. An ectopic kidney is present above, below or on the opposite side of the normal position of the kidneys.

The kidneys of fetuses appear in the form of buds at first. These buds appear in the pelvis region. With the passage of time, they travel upwards and occupy normal position. In cases of ectopic kidneys;

  • Kidney may move too slow and remain in the pelvis region.
  • Both kidneys may occupy the same side of the body.
  • Kidney may move very fast and go far above the normal position.

What are the causes of ectopic kidney?

Birth defects are quite difficult to track back for identifying their causes. The same is the case with ectopic kidney cases. Some possible causes can be;

  • A genetic defect.
  • Drug abuse.
  • A kidney bud that does not develop properly.
  • Problems linked with the tissues that direct the movement of kidney buds in fetuses.

How is ectopic kidney diagnosed?

Prenatal ultrasound is the main diagnostic tool for ectopic kidney. This is because if people do not have prenatal ultrasounds, they may never know about having an ectopic kidney. Different types of lab tests for the urinary tract also diagnose this condition.

What is the treatment for ectopic kidney?

Firstly, an ectopic kidney causes no symptoms. This is the reason that no specific treatments are needed. Secondly, It is very rare that both kidneys tend to be ectopic. Even if some issues occur, doctors choose follow-ups or surgeries in worst cases.

5. Renal Agenesis

Renal agenesis is also a birth defect. This means that this condition occurs during pregnancy and before the baby is born. In this condition, the fetus has either one kidney or no kidneys at all. There are two types of renal agenesis:

  • Unilateral renal agenesis where one kidney is formed. These babies live their entire lives with a single kidney.
  • Bilateral renal agenesis where both kidneys are absent. Such fetuses do not produce any urine at all.

Renal agenesis is a very rare disease. For instance, unilateral renal agenesis has a 1:2000 ratio. Similarly, bilateral renal agenesis has 1:4500 ratio. These ratios are for live birth cases.

What are the causes of renal agenesis?

No specific causes of both unilateral and bilateral renal agenesis are known. But it is generally consider as a genetic disorder. Intrauterine growth restriction has also been associated with renal agenesis. Pregnancies including twins or multiples are also linked with this birth defect. Intake of alcohol, drugs, certain medications and nicotine can also cause renal agenesis in the unborn babies.

How renal agenesis is diagnosed?

Prenatal ultrasounds are the basic mediums through which renal agenesis is diagnosed. These images let the doctors know about the presence, absence, and development of the kidneys. Since they are done at different gestational ages, proper development is easy to track. Doctors also suggest using genetic testing in such cases.

What is the treatment for renal agenesis?

  • There is no treatment for bilateral renal agenesis. The absence of both kidneys makes it very difficult for the fetus to survive.
  • In the case of unilateral renal agenesis, things go fine as long as there is enough amniotic fluid for the fetus.
  • After birth, doctors suggest regular follow-ups to keep a check on the changing situations.


All in all, baby kidney problems in pregnancy vary among pregnancies. Parents need to choose regular screening to catch any defect right from the beginning. This is the path to success. Timely diagnoses allow doctors and parents to work together. They try ways to help the fetus as much as is possible before birth.

We would be very happy to hear from you on the comments sections of our Facebook page. You can also visit our Quora page. Feel free to leave your comments and queries about baby kidney problems in pregnancy.

About The Author

Affaf Amjad

Having an MPhil in Applied psychology and being a mother of three kids, I have always tried to try and test different psychological interventions and approaches in the day-to-day routine of my kids. Sharing my results and effective strategies with parents around the globe is the my main aim as a writer.

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