1.What is congenital hydronephrosis?
The kidneys are the filtering plant for the body’s blood. The blood that flows into the kidneys is filtered by the kidneys, and the waste products in the blood are filtered to form urine, which is collected by the renal pelvis and goes down the ureter into the bladder and then out of the body.
The renal pelvis is the place where urine collects (the yellow, overall antler-like area is the pelvis, which collects urine made by the surrounding kidney tissue and injects it into the pelvis to pool downward to form the ureter), and all normal urine can flow smoothly downward through the ureter into the bladder from there.
Ninety percent of congenital hydronephrosis can be classified as I obstructive and II reflux type. The obstructive type refers to the two parts of the lower aqueduct, the renal pelvis and the ureter, where either part is narrowed and there is inevitably a dilation above the narrowing. It is the same as when a 4-lane road suddenly becomes a 1-lane road, there is bound to be a traffic jam. The reflux type refers to the reflux of urine from the bladder into the renal pelvis (equivalent to a car going in reverse, which can lead to a serious traffic accident), which can also lead to hydronephrosis and ureteral dilatation.
Usually, congenital hydronephrosis is only on one side, but occasionally bilateral congenital hydronephrosis is seen.
2. What risk factors predispose the fetus to congenital hydronephrosis?
There are no clear specific factors that lead to congenital hydronephrosis, but a large number of epidemiological statistics show that boys are more likely to develop congenital hydronephrosis than girls, and the odds are about 4 to 5 times higher than for girls.
There are no factors that can definitely cause hydrocele, such as any behavior during pregnancy, dietary habits, etc. In short, there is almost nothing that cannot be done during pregnancy to prevent the development of congenital hydrocele.
Of course, practices such as smoking and alcohol abuse that are harmful to embryonic development should still be actively avoided.
3. Is congenital hydronephrosis common?
Yes, congenital hydronephrosis is relatively common, about 1 out of 100 newborns will have congenital hydronephrosis.
In the fetal period, most of them are detected by ultrasound during the delivery.
In childhood, most of them are found when the child has abdominal pain or hematuria and goes to the hospital for ultrasound examination.
4.When can congenital hydronephrosis be detected during pregnancy at the earliest?
The kidneys start working to produce urine when the fetus is about 10 weeks to 12 weeks after fertilization. However, most ultrasonographers can only detect congenital hydronephrosis by ultrasound after the fourth month of pregnancy.
5. Should I specifically ask my doctor to do ultrasound to diagnose congenital hydronephrosis during pregnancy?
This is not necessary at all. During a normal obstetric examination, the ultrasonographer will routinely look for signs of congenital hydronephrosis with other diseases.
6. To what extent can ultrasound during pregnancy assess congenital hydronephrosis?
Ultrasound during pregnancy is very helpful in understanding fetal hydronephrosis. However, fetal tissues are extremely elastic, which means that “the hydrocele seen on ultrasound may be more severe than it actually is,” which is why ultrasound doctors and obstetricians ask pregnant women to be closely followed up.
7.Does congenital hydronephrosis have any serious adverse effects on the fetus?
Most fetuses do not require treatment after the diagnosis of congenital hydronephrosis, as long as the ultrasound is closely monitored. Only in rare cases, the fetus with hydronephrosis has too little urine, resulting in a decrease in amniotic fluid. If the amniotic fluid is too little, it will have an impact on the development of the fetus.
8.Obstetrical examination reveals that the baby has congenital hydronephrosis, can the baby still be born?
According to current clinical studies, 70% of babies with congenital hydronephrosis found at delivery are mild to moderate, so they can be delivered without problems. More than 90% of babies with congenital hydronephrosis can grow up healthy and do not need to worry.
9.Can a fetus with congenital hydronephrosis be delivered successfully?
The majority of fetal hydronephrosis has no effect on pregnancy and delivery.
10.What are the causes of congenital hydronephrosis?
(1) Obstructive causes include: ureteropelvic junction stenosis, ureterobladder junction stenosis, ureteral cyst and ectopic ureteral opening (the ureter-bladder junction is different than normal), neurogenic bladder (the bladder is not innervated due to abnormal nerve function and urine reflux occurs), posterior urethral valve (a valve appears at the bladder-urethra junction), urethral atresia, vaginal uterine effusion, etc.
(2) Non-obstructive etiologies are: primary vesicoureteral reflux, physiological pelvic calyces dilatation and Prune-Belly syndrome.
11.What are the risks of congenital hydronephrosis?
The main ones are infection and impairment of kidney function.
Can the kidney not be infected due to fluid accumulation (a pool of stagnant water? Clear water is living water, but stagnant pools are foul-smelling) cannot be discharged from the body, leading to urinary tract infections and fever; either more and more water accumulates, compressing the kidney cortex with filtration function (that is, the place with real filtration function), leading to serious damage to kidney function, or even completely destroying the function of one kidney and removing it, bringing lifelong regret to the baby.
12.What are the signs of congenital hydronephrosis?
Mild to moderate congenital hydronephrosis has no clinical manifestations or discomfort.
Common clinical manifestations in babies under 2 years of age include abdominal distention, abdominal mass, urinary tract infection (mainly manifested by fever with no apparent cause), hematuria, and purulent urine.
In older children (over 5 years old), most of them will report abdominal pain during urination, hematuria, abdominal pain on one side, acute urinary tract infection manifestations (frequent, urgent, painful urination), pus urination, etc.
13.What are the diagnostic methods of congenital hydronephrosis?
For hydrocele in the fetus, the only diagnostic method that can be done is the ultrasound of labor and delivery. Ultrasound can tell the size of the fetal kidney, the severity of hydrocele, the amount of amniotic fluid, and suggest the possible cause of hydrocele.
For older children, the following tests can be done.
1.Urological ultrasound;
2.Intravenous urography + CT scan;
3. Cystogram;
4.Magnetic resonance imaging (MRI)
14.What is intravenous urography?
In layman’s terms, it is a way of injecting a special drug that is used to fill the urinary tract with the degree of smoothness of its course. This drug is not absorbed by the body, but happens to be excreted completely through the kidneys, and when it passes through the kidneys, it can also be ray-probed to react on the instrument, called contrast agent. The contrast agent is used to stay in the kidney for this brief period of time (about an hour or so) and is recorded with X-rays to assess the shape of the renal pelvis and ureter.
15.What is a cystogram?
Similar to intravenous urography above, a certain drug is injected into the bladder using a catheter that enters the bladder through the urethra. This medication can also be radiographed to assess the shape of the bladder and the reflux of the vesicoureter.
16. How is the severity of congenital hydronephrosis classified?
For the population, congenital hydronephrosis is broadly classified as mild, moderate, or severe.
17.How is congenital hydronephrosis treated?
Most cases of hydronephrosis in the fetus (before delivery) can be treated with follow-up ultrasound, and treatment of hydronephrosis caused by posterior urethral valves in the fetus has been reported overseas.
Most newborns born with mild to moderate hydronephrosis also do not require treatment (70% of congenital hydronephrosis) and should be followed up.
For the remaining children with moderate to severe hydronephrosis, most require a combination of surgical treatment.
18.What should I do next after delivery of a fetus with congenital hydronephrosis?
At the beginning, the doctor may give the newborn a small amount of oral antibiotics for about 2~3 weeks depending on the condition of hydrocele. If the hydrocele is only mild, then no treatment is needed.
19.Will my first baby with congenital hydronephrosis still have congenital hydronephrosis in subsequent pregnancies?
It is highly unlikely. Because congenital hydronephrosis is not a genetic disease, and hydronephrosis is not clearly associated with lifestyle habits during pregnancy.
20.What are the cases of fetal hydronephrosis that require intervention?
In rare cases, hydrocele in the fetus requires urgent treatment and management. A small percentage of fetuses have a posterior urethral valve that blocks the connection between the bladder and urethra, and finally the maternal amniotic fluid is so low that it may endanger the life of the fetus.
All the rest can be observed by regular follow-up visits as required by the doctor.
21.After birth, when should congenital hydronephrosis be treated?
If ultrasound and imaging tests clearly identify the presence of pelvic ureteral obstruction/stenosis, or ureteral bladder obstruction and other organic diseases, surgery should be performed as soon as possible to solve these problems and save the kidney function.
22.My child has congenital hydronephrosis, will he need dialysis treatment?
It is unlikely that dialysis will be used to treat congenital hydronephrosis. As long as one of the newborn’s kidneys is normal, he will survive well.
23. What should I expect in a child with hydronephrosis during follow-up visits?
For infants, general daily life as normal infant feeding is sufficient.
Take care to avoid unhygienic infections, improve physical exercise, and watch for cloudy urine (which may indicate a urinary tract infection).
When visiting a pediatrician after the onset of febrile manifestations, be sure to tell the receiving physician of the presence of a history of congenital hydronephrosis, and the receiving physician will usually perform a routine urinalysis.
For older children, the same is to enhance physical exercise, drink more water on a daily basis, do not hold urine, and observe the nature of urine.
24.What should I do if I have congenital hydronephrosis combined with urinary tract infection?
At this time, you should not hesitate to seek immediate medical attention and regular anti-infection treatment.
25.What surgical procedures are available for congenital hydronephrosis of different causes?
Depending on the cause of congenital hydronephrosis, surgical procedures include pelvic ureteroplasty, stenotic ureterotomy anastomosis, ureteral bladder reimplantation, etc.
26.Is the cure rate of congenital hydronephrosis surgery high?
Surgery is the most effective means to treat congenital hydronephrosis. With the most common pyeloureteroplasty, the overall success rate has reached 90%, the surgical result is satisfactory, and the chance of postoperative complications and recurrence is also very low.
27.Can I live like a normal person after surgery?
The growth and development of children cured by surgery should be no different from normal people. However, for children with severe hydronephrosis, because the kidney function has been destroyed before surgery, the destroyed kidney cannot be recovered. Therefore, early surgical treatment for children with congenital hydronephrosis is emphasized, and those without surgery should be closely followed up and observed.
28.What are the common complications after congenital hydronephrosis surgery?
The common ones are urinary tract infection, anastomotic stenosis, vesicoureteral reflux, etc.
29.What should I do if there are complications after congenital hydronephrosis?
The underlying cause of the complication should be clarified, such as urinary tract infection, which requires a regular long course of oral antibiotics; if the anastomotic stenosis is narrowed, reoperation to release the narrowed segment should be considered; for vesicoureteral reflux, follow-up observation or reoperation should also be considered depending on the condition.
30.What should I pay attention to after surgery for congenital hydronephrosis?
Insist on regular follow-up visits to observe the recovery of the expansion of the renal pelvis. Drink more water in daily life to keep the urinary tract open.