Renal agenesis is a birth condition where one kidney or, more rarely, both kidneys do not develop. Many people with unilateral renal agenesis have no symptoms and find it during a scan done for another reason or during childhood or adulthood. It may help to know that doctors have studied this condition for decades, and many living with renal agenesis do well with one healthy kidney and lifelong follow-up. Bilateral renal agenesis is usually found before birth and is very serious because it can prevent normal lung development and is often fatal around birth. Treatment for renal agenesis depends on whether one or both kidneys are affected and may include regular checkups, blood pressure care, and support from kidney specialists.
How many people live with Renal agenesis?
Direct worldwide and U.S. counts are not kept in one central registry, but based on the Fetal Medicine Foundation estimate that the more common form of renal agenesis, being born with one kidney instead of two, happens in about 1 in 2,000 births, roughly 4 million people worldwide may be living with it today (Fetal Medicine Foundation, 2024; United Nations, 2024). Using the same estimate, about 170,000 people in the United States may be living with renal agenesis, although this is an estimate rather than a direct count (Fetal Medicine Foundation, 2024; U.S. Census Bureau, 2024).
Overview
Renal agenesisSymptoms
Renal agenesis often causes no symptoms when one kidney is missing, and many people feel well. When both kidneys are absent, severe signs usually appear before birth or at delivery, including very low amniotic fluid and underdeveloped lungs.
Outlook and prognosis
Outlook in renal agenesis depends on whether one or both kidneys are missing. Many with one kidney live normal, healthy lives with regular checkups. When both are missing, survival is usually not possible after birth.
Causes and risk factors
Renal agenesis usually happens before birth when a kidney does not develop, often due to a new genetic change or, less often, an inherited one. Risk may rise with diabetes, smoking, heavy alcohol use, and some medicines during pregnancy.
Genetic influences
Genetics can be important in renal agenesis, especially when it runs in families or happens with other birth differences. Genetic variations may raise risk, but many people with renal agenesis have no clear inherited cause.
Diagnosis
Renal agenesis is often diagnosed before or after birth using ultrasound imaging that shows one or both kidneys are missing. The diagnosis of renal agenesis may be confirmed with imaging findings, clinical features, and sometimes genetic tests.
Treatment and drugs
Treatment for renal agenesis depends on whether one or both kidneys are missing. With one kidney, most people need regular checkups and blood pressure care. When both are missing, care centers on intensive newborn support and kidney transplant.
Symptoms
Renal agenesis means a baby is born missing one kidney or, less often, both kidneys. For many people with renal agenesis, day-to-day life depends on whether one kidney or both kidneys are absent. When only one kidney is missing, there may be no obvious early features of renal agenesis, and it may be found by chance on a scan. When both kidneys are absent, serious problems usually begin before birth or right after delivery, and this form is often life-threatening.
Many people born with one kidney missing feel completely well and have no clear warning signs. It is often found later during an ultrasound or other imaging done for a different reason.
If both kidneys are absent, the baby makes little or no urine before birth, so the fluid around the baby stays very low. This can limit space in the womb and affect how the lungs and body develop.
Babies with both kidneys missing often have severe breathing problems at birth because the lungs did not fully develop in the womb. This needs urgent medical care and is often life-threatening.
Very low fluid before birth can lead to a flatter nose, lower-set ears, and hands or feet that are held in unusual positions. These are signs doctors may notice at birth rather than symptoms the baby can describe.
How people usually first notice Renal agenesis?
How renal agenesis is first noticed often depends on whether one kidney or both failed to develop. In many pregnancies, the first signs of renal agenesis show up on a prenatal ultrasound, where doctors may see a missing kidney or, in bilateral renal agenesis, very low amniotic fluid because the baby is not making urine normally. If only one kidney is absent, many people with renal agenesis have no early symptoms and it may first be found during a newborn check, an ultrasound for another reason, or later in childhood when a doctor notices they have a single working kidney.
Types of Renal agenesis
Renal agenesis can affect day-to-day life very differently depending on whether one kidney is missing or both are missing. In this congenital condition, the main variants of renal agenesis are defined by whether the absence involves one kidney or both, and that difference strongly shapes symptoms and severity. Symptoms don’t always look the same for everyone. Many people with one missing kidney feel well for years, while bilateral renal agenesis causes severe problems before or right after birth.
Unilateral renal agenesis
One kidney does not develop, and many people have no clear symptoms because the other kidney often does enough work on its own. Some may find it is discovered by chance during imaging for belly pain, pregnancy care, or another health check. When symptoms do occur, they can include urinary tract infections, high blood pressure, or reduced kidney function later in life.
Bilateral renal agenesis
Both kidneys do not develop, which leads to very low amniotic fluid during pregnancy and severe problems with lung development before birth. Babies with this form usually have life-threatening breathing trouble at delivery and cannot make urine normally because no kidneys are present. This type of renal agenesis is much more severe than the unilateral form.
Can I slow down the onset of symptoms?
No, not in the usual sense: renal agenesis means a baby is born with one or both kidneys missing, so there is no proven way to delay when it begins. If someone has one working kidney, healthy habits like not smoking, keeping blood pressure in a healthy range, staying well hydrated, and avoiding kidney injury may help protect that kidney and lower the risk of later kidney problems, but they do not prevent the condition itself. Regular checkups to monitor blood pressure, urine, and kidney function are a standard part of care, and while they cannot change the condition, they can help many people living with renal agenesis stay as healthy as possible.
What genetics can tell you about symptoms
Genetics can sometimes help explain why renal agenesis happens and whether it shows up on its own or as part of a broader genetic condition that can affect other parts of the body, such as the urinary tract, genitals, ears, or heart. In some families, certain genetic changes are linked to a higher chance of kidney and urinary tract differences, but they usually do not let doctors predict exactly which symptoms will appear, how severe they will be, or when problems will be noticed. For many people, day-to-day effects depend more on whether one kidney is missing or both, and on how well the remaining kidney and related organs develop, than on the specific genetic finding alone.
Causes and risk factors
Renal agenesis usually begins very early in pregnancy, when an inherited or new gene change affects how the kidneys form. Many of the known risk factors for renal agenesis are present before birth, including a family history and some genetic or chromosome conditions. On top of genetics, everyday habits also matter. Poorly controlled diabetes before or during pregnancy can raise the chance. Smoking, heavy alcohol use, and some medicines taken in pregnancy may also increase risk, but many cases happen without any clear cause.
What are the most common causes or risk factors?
Renal agenesis happens when a kidney does not form very early in pregnancy, and in many cases there is no single clear cause. The main known risk factors are a family history of missing kidneys or other urinary tract birth differences, and inherited genetic changes that affect how the kidneys develop. During pregnancy, poorly controlled diabetes and exposure to tobacco, alcohol, or some medicines and illegal drugs may also raise the risk.
Environmental and biological risk factors
When people read about risk factors for renal agenesis, it helps to remember that not every case has a clear cause. Doctors often group risks into internal (biological) and external (environmental). The best-supported non-genetic links are certain maternal health conditions, sex-based patterns, and some harmful exposures early in pregnancy, when the kidneys are first forming.
Diabetes in the mother, especially if it is present before pregnancy or not well controlled early on, can raise the chance of kidney development problems. This includes a higher risk of renal agenesis and other urinary tract differences.
Some medicines known to cause birth defects, such as strong vitamin A acne drugs, can interfere with normal kidney formation if exposure happens early in pregnancy. This is why medication review before or early in pregnancy is important.
High-dose radiation exposure early in pregnancy can disrupt normal organ formation. Although uncommon, it is a recognized environmental risk for serious urinary tract birth differences, including renal agenesis.
Renal agenesis is diagnosed somewhat more often in male babies than in female babies. This is a background biological pattern seen in studies, not something parents can change.
Genetic risk factors
Renal agenesis can sometimes happen because of changes in genes that guide kidney development before birth, and it may run in families. In other families, the cause is not found even after testing, because the genetic causes of renal agenesis are still being worked out. Carrying a genetic change doesn’t guarantee the condition will appear. The chance of a genetic explanation is often higher when renal agenesis affects both kidneys, happens with other birth differences, or appears in close relatives.
Family history: Having a parent, sibling, or child with renal agenesis or another kidney or urinary tract birth difference can raise the chance in a family. This is because related conditions can share the same inherited genetic tendency. The pattern can vary, so one relative may be mildly affected while another is more clearly affected.
Inherited gene changes: Some people with renal agenesis have a change in a gene that helps build the kidneys early in pregnancy. Genes linked to this include GREB1L and RET, but no single gene explains all cases.
New genetic changes: Sometimes the genetic change is new in the child and was not inherited from either parent. When this happens, there may be no family history even though the cause is still genetic.
Genetic syndromes: Renal agenesis can be part of a broader inherited condition, especially when it occurs along with differences involving the ears, eyes, limbs, or urinary tract. Examples include conditions related to HNF1B, PAX2, EYA1, and SALL1.
Chromosome changes: In some cases, a missing or extra piece of a chromosome can disrupt several genes involved in kidney formation. This type of genetic change is more often considered when renal agenesis appears with other birth differences or developmental concerns.
Lifestyle risk factors
Renal agenesis is present from birth, so lifestyle habits do not cause it. However, how lifestyle affects renal agenesis can matter a great deal, especially for people living with one kidney or with related urinary tract issues. Daily habits can influence kidney workload, blood pressure, hydration, and the chance of complications over time.
Poor fluid intake can raise the risk of dehydration, which may put extra stress on a single functioning kidney. Steady hydration may help support kidney filtration and lower the chance of some urinary problems.
Eating a very salty diet can increase blood pressure, which can gradually damage the remaining kidney. Choosing lower-sodium meals may help protect kidney function over time.
Very high protein intake, especially from supplements or extreme diets, can increase the kidney's filtering workload. In some people with renal agenesis, avoiding unnecessary excess may help reduce long-term strain.
Carrying excess weight can raise the risk of high blood pressure, diabetes, and kidney stress in someone with renal agenesis. Regular, moderate physical activity can support cardiovascular health and help protect the remaining kidney indirectly.
Risk prevention
Renal agenesis happens when one or both kidneys do not form before birth, so there is usually no way to fully prevent the condition itself once development has begun. Prevention is about lowering risk, not eliminating it completely. For families thinking about pregnancy, the focus is on reducing avoidable risks, managing health conditions before and during pregnancy, and finding any concerns early. This matters most for bilateral renal agenesis, the more serious form where both kidneys are absent.
A checkup before pregnancy can help review health conditions, past pregnancy history, and possible risk factors for renal agenesis. This gives time to improve overall health and lower avoidable risks before early kidney development begins.
Poorly controlled diabetes in pregnancy can raise the chance of some birth differences, including problems affecting the kidneys. Getting blood sugar into a safer range before conception and in early pregnancy may help reduce that risk.
Some medicines can interfere with fetal kidney development, especially if taken in early pregnancy. A doctor or pharmacist can help switch unsafe medicines to safer options before pregnancy when possible.
Alcohol, smoking, and nonprescribed drugs can increase the risk of birth defects and may affect how organs develop. Avoiding these exposures before and during pregnancy is one of the clearest steps that may help lower risk.
Can you prevent Renal agenesis?
Usually, no, renal agenesis cannot be fully prevented because it happens very early in pregnancy when one or both kidneys do not form, and in many cases the exact cause is unknown. Some risks may be lowered by getting good care before and during pregnancy, especially by keeping diabetes well controlled, avoiding smoking, alcohol, and illegal drugs, and reviewing any medicines with a doctor before taking them. Even when you do everything right, this condition can still happen, so prevention is not always possible.
Transmission
Renal agenesis is not infectious, so it cannot be caught from someone else through close contact, the air, food, sex, or blood. Instead, it develops before birth, and many cases happen by chance while the baby is forming in the womb.
In some families, Renal agenesis is linked to a gene change that can be passed from parent to child, while in others it appears as a new change in the child with no family history. Because the causes vary, how Renal agenesis is inherited is not always simple, and the chance of it happening again in a family depends on whether one kidney or both are affected and whether it is part of a broader genetic condition.
When to test your genes
Consider genetic testing if a prenatal ultrasound shows a missing kidney, if kidney absence affects both sides, or if there are other birth differences. Testing is also worth discussing when renal agenesis runs in your family, because results can help clarify recurrence risk and guide kidney and hearing follow-up.
Diagnosis
Renal agenesis is often found before birth on a routine ultrasound or soon after delivery if a baby has features that suggest a missing kidney. In many living with one missing kidney, there may be no symptoms at all, and the diagnosis of renal agenesis happens during imaging done for another reason. Doctors confirm the finding with scans and also check whether the urinary tract and other organs developed as expected.
Many cases are first suspected during pregnancy when an ultrasound does not show one or both kidneys. The scan may also show low amniotic fluid if both kidneys are missing, which can be a serious sign.
After birth, doctors look at breathing, growth, blood pressure, and signs of other birth differences that can occur alongside renal agenesis. Getting a diagnosis is often a turning point toward answers and support.
An ultrasound after birth is usually the main test to confirm that a kidney is absent. It also helps check the size and shape of the remaining kidney and whether it has grown larger to do extra work.
Your provider may suggest imaging tests to look closer at the bladder and urine drainage system if another urinary tract problem is suspected. These scans can help find reflux, blockage, or structural differences that sometimes occur with renal agenesis.
How is Renal agenesis diagnosed?
Renal agenesis, which means a baby is born with one kidney missing or, more rarely, both kidneys missing, is often found on a routine ultrasound during pregnancy or confirmed after birth with an ultrasound of the kidneys and urinary tract. Doctors may also use blood and urine tests to see how well the kidneys are working, and sometimes other scans if they need a closer look at the bladder, tubes from the kidneys, or the one working kidney. Genetic testing is not always needed, but it may be offered if there are other birth differences, a family history, or signs that the missing kidney is part of a broader inherited condition.
Stages of Renal agenesis
Renal agenesis does not have defined progression stages. This is because it is a difference in kidney development that happens before birth, rather than an illness that gradually moves from one stage to another over time. Doctors usually start with a conversation about symptoms and overall health, then use imaging tests such as ultrasound to confirm whether one kidney or both kidneys are absent. In people with one missing kidney, follow-up often includes blood pressure checks, urine tests, and blood tests to watch kidney function, while the early symptoms of renal agenesis may only become noticeable if the single working kidney is under strain or if other urinary tract differences are present.
Outlook and prognosis
The outlook for renal agenesis depends almost entirely on whether one or both kidneys are absent. Unilateral renal agenesis often has a good prognosis, and many people live normal lifespans with one healthy kidney, although they may have a higher risk of high blood pressure, proteinuria, and reduced kidney function over time, so long-term follow-up is recommended. Bilateral renal agenesis has a very poor prognosis because the fetus cannot make enough urine to support normal lung development, and it is usually fatal before birth or shortly after delivery. In rare cases where intensive neonatal care and later dialysis and kidney transplantation are possible, short-term survival may occur, but this remains uncommon. Mortality is therefore low for isolated unilateral renal agenesis and extremely high for bilateral renal agenesis.
Long-term effects
For many people with renal agenesis, the long-term picture depends mostly on whether one kidney is missing or both. Long-term effects vary widely, and many living with unilateral renal agenesis do well for years with one working kidney. When both kidneys are absent, the condition usually causes severe problems before or shortly after birth, especially because the lungs may not develop fully.
If both kidneys are missing, survival is often not possible without intensive newborn care and, in selected cases, dialysis soon after birth. A major reason is poor lung development before birth, which can cause severe breathing failure at delivery.
With one kidney, the body often grows a larger working kidney that can handle daily needs well. Even so, there is less backup if that kidney is injured or develops disease later in life.
Over time, some people with unilateral renal agenesis develop high blood pressure because a single kidney may be under extra strain. This may not cause obvious early symptoms of renal agenesis and is often found on routine checks.
Some may develop protein leaking into the urine or a gradual drop in kidney function over many years. In a smaller group, this can lead to chronic kidney disease in adolescence or adulthood.
How is it to live with Renal agenesis?
Living with renal agenesis can mean very different things depending on whether one kidney is missing or both. Many people with unilateral renal agenesis, where one kidney never formed, grow up healthy and live full lives, though they are usually advised to protect their single working kidney with regular checkups, good blood pressure control, and caution with dehydration, certain medicines, and high-impact injuries. For families, this can bring extra medical visits and some worry, but it also often becomes a manageable part of life; bilateral renal agenesis is far more severe and is usually recognized before or shortly after birth, with major medical and emotional effects on loved ones.
Treatment and drugs
Treatment for renal agenesis depends on whether one kidney is missing or both are missing. When only one kidney is absent, many people do well without daily medicine, but care usually focuses on protecting the working kidney with regular checkups, blood pressure control, and quick treatment of urine infections if they happen. Doctors sometimes recommend a combination of lifestyle changes and drugs, such as medicines to lower high blood pressure, and they may advise avoiding medicines that can strain the kidney, including frequent use of some pain relievers like ibuprofen. If both kidneys are absent, this is a life-threatening condition that often needs intensive newborn care, and for babies who survive, treatment may include dialysis to do the kidneys' job and later a kidney transplant. Because the best plan can differ a lot from one child or adult to another, care is usually guided by a kidney specialist.
Can you cure Renal agenesis?
No, renal agenesis, which means being born with one or both kidneys missing, cannot be cured because a missing kidney cannot be made to grow back. If only one kidney is missing, many people do well with regular checkups and steps to protect the kidney they have. If both kidneys are missing, treatment is much more complex and may involve intensive medical support, dialysis to do the job of the kidneys, and sometimes a kidney transplant.
Non-drug treatment
Day-to-day care for renal agenesis depends a lot on whether someone is living with one working kidney or has more severe kidney failure. Many people with unilateral renal agenesis feel well and mainly need regular follow-up to help protect the kidney they have. Managing this condition often centers on kidney-safe habits, blood pressure control, and watching for urinary problems or related birth differences. In severe cases, supportive care may also include dialysis, transplant planning, and counseling for families.
Checkups help track blood pressure, urine protein, and how well the kidney is filtering over time. For many living with renal agenesis, this is a key part of treatment for unilateral renal agenesis, even when there are no symptoms.
Staying well hydrated, keeping a healthy weight, and avoiding smoking can lower strain on the kidney. Contact sports may need extra discussion with a doctor, since some people with one kidney benefit from added protection or activity changes.
A balanced eating pattern with sensible salt intake can help support blood pressure and kidney health. Some may also meet with a kidney dietitian if lab tests show reduced kidney function or if growth and nutrition are concerns in childhood.
Home blood pressure checks, regular exercise, and limiting excess sodium can help protect the remaining kidney. Even small changes can lead to steadier blood pressure over time.
Your genes may have an impact on how drugs work for you
For people living with renal agenesis, the missing kidney itself usually matters more than inherited differences when it comes to medicines, because many drugs leave the body through the kidneys and may build up if dosing is not adjusted. Still, natural genetic differences can make some people break down certain medicines faster or slower, which can affect how well some pain medicines, blood pressure treatments, or antibiotics work or how likely they are to cause side effects. In everyday life, this can mean one person does well on a usual dose while another needs a lower dose or closer follow-up, especially when there is only one working kidney.
Pharmacological treatments
For many living with renal agenesis, there is no medicine that can replace a missing kidney, and treatment depends on whether one kidney is working well and whether complications develop. The medications used for renal agenesis are mainly used to manage related problems such as urine infections, high blood pressure, swelling, anemia, or mineral imbalance. Medication can feel like a big step, but many people with one healthy kidney may not need regular drugs at all. When both kidneys are absent or do not work well enough, medicines are usually part of broader kidney care.
Antibiotics such as amoxicillin, cephalexin, trimethoprim-sulfamethoxazole, and nitrofurantoin may be used if renal agenesis is linked with repeated urinary tract infections. The exact choice depends on age, kidney function, allergies, and local resistance patterns.
Medicines such as lisinopril, enalapril, losartan, and valsartan are often used when people with renal agenesis develop high blood pressure or protein leaking into the urine. These drugs can help protect the remaining kidney, but blood tests are usually needed to watch kidney function and potassium levels.
Diuretics such as furosemide or bumetanide may be used if poor kidney function causes fluid buildup, puffiness, or shortness of breath. Dosing may be increased or lowered gradually to control swelling without causing dehydration.
If chronic kidney disease develops, epoetin alfa or darbepoetin alfa may be used to help the body make more red blood cells, and iron may also be prescribed. This can improve fatigue and exercise tolerance, especially in people whose kidney disease is more advanced.
Genetic influences
Families often ask about the genetic causes of renal agenesis, especially after a pregnancy scan or birth exam shows that one kidney did not form. It’s natural to ask whether family history plays a role. In many cases, renal agenesis happens without one clear cause, but changes in genes that guide kidney development before birth can sometimes contribute, and some families do have more than one affected relative. A few genes, including PAX2 and HNF1B in some families, have been linked to renal agenesis, and the condition can also occur as part of a broader genetic syndrome or a chromosome change. Even when a gene change is found, the effects can vary a lot, so one family member may have a missing kidney while another has milder urinary tract differences or no obvious symptoms. If renal agenesis seems to run in the family, genetic counseling can help explain the chance of it happening again and whether genetic testing may be useful.
Is Renal agenesis genetic?
Genetics can be important in renal agenesis, especially when it runs in families or happens with other birth differences. Genetic variations may raise risk, but many people with renal agenesis have no clear inherited cause.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are common and are a normal part of being human. Most do not directly affect health and simply make up part of the natural differences seen across people. For many genes, having a variant connected to a condition points to a possible link rather than a certain diagnosis, especially when several genes and environmental factors are involved. In some situations, though, one well-understood variant in a particular gene is enough to confirm the diagnosis.
Pharmacogenetics—how genetics influence drug effects
For many living with renal agenesis, treatment is less about a medicine for the missing kidney and more about protecting overall kidney health over time. Genetics can help explain why renal agenesis happened and whether it is part of a broader inherited condition, which may shape follow-up care and screening for related problems. Not every difference in response is genetic, but genes and kidney function together can affect which drugs are safest and what dose is needed, especially when someone has only one working kidney or reduced kidney function. Doctors often use extra caution with medicines cleared by the kidneys, such as some antibiotics, pain relievers, and blood pressure medicines, because the right dose may differ from what is used in people with two healthy kidneys. In practice, this means treatment for renal agenesis is usually personalized around lab results, blood pressure, and any complications like urinary infections or chronic kidney disease, rather than around a single standard drug plan. Pharmacogenetic testing is not routine for renal agenesis itself, but if another condition needs treatment, genetic test results can sometimes help doctors choose a medication with a better chance of working well and causing fewer side effects.
Interactions with other conditions
For many people living with renal agenesis, the bigger day-to-day issue is not the missing kidney itself but whether the remaining kidney stays healthy and whether other body systems are also affected. Renal agenesis can occur along with urinary tract problems such as urine flowing backward from the bladder toward the kidney, which can raise the risk of urinary infections and, over time, kidney damage. It may also appear with differences in the genitals or reproductive organs, so some people only learn about these related conditions later, such as during puberty, fertility testing, or pregnancy care. Doctors call it a “comorbidity” when two conditions occur together. When renal agenesis is part of a broader genetic or developmental pattern, there may also be hearing, heart, or skeletal differences, although this varies widely from person to person. Because people with a single working kidney can be more vulnerable if they also develop high blood pressure, diabetes, or repeated kidney infections, regular follow-up is important to help protect long-term kidney function.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Renal agenesis?
Other kidney and urinary tract problems can look a lot like renal agenesis, including a kidney that is there but very small, poorly formed, or sitting in an unusual place, as well as damage from a blockage that keeps urine from draining normally. Some inherited kidney conditions and other causes of low kidney function can also cause similar problems, such as high blood pressure, swelling, repeated urine infections, or poor growth in babies and children. Doctors usually tell these apart with scans and simple kidney function tests.
History
For much of history, renal agenesis was only recognized after birth or during an examination after death. Babies with bilateral renal agenesis, where both kidneys do not form, were often very sick from the start because the condition also affects lung development before birth. When only one kidney was missing, though, many people grew up never knowing it; the finding might surface years later during a scan for stomach pain, high blood pressure, or an unrelated injury.
In recent decades, awareness has grown as pregnancy ultrasound became routine and doctors could see the kidneys developing before birth. That changed the story for many families. Instead of the condition being discovered only after serious problems, renal agenesis could sometimes be spotted during pregnancy or picked up incidentally in childhood or adulthood when imaging was done for another reason.
Earlier medical descriptions focused on what doctors could see, not why it happened. Over time, descriptions became more accurate as imaging improved and specialists learned to separate renal agenesis from other kidney differences, such as a very small kidney or a kidney that developed in an unusual position. This mattered because the outlook can be very different if one kidney is absent versus both.
The history of renal agenesis also reflects a broader shift in medicine: moving from description to earlier diagnosis, closer monitoring, and better support. Researchers later identified that some cases have a genetic cause, while others seem to happen without a clear family pattern. Still, not every early description was complete, yet together they helped build today’s understanding of the condition and why follow-up matters.
Today, many living with unilateral renal agenesis, meaning one kidney did not develop, can live full and healthy lives with routine medical care. At the same time, the history of bilateral renal agenesis helps explain why it remains a very serious condition. Knowing this background can make modern care easier to understand, especially when families are hearing about early symptoms of renal agenesis, prenatal scan results, or long-term kidney checkups for the first time.