My Baby Has Posterior Urethral Valves (PUV)
Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist
Content reviewed against published NIH, AAP, Children's Hospital guidelines
Last reviewed:
If your baby has been diagnosed with or you suspect has posterior urethral valves (puv), here is what the evidence says.
The short answer
Posterior urethral valves (PUV) are abnormal folds of tissue in the urethra of boys that block the flow of urine out of the bladder. PUV is the most common cause of lower urinary tract obstruction in male newborns. It is often detected on prenatal ultrasound when bilateral hydronephrosis (swelling of both kidneys) and a distended bladder are seen. After birth, boys may have a weak or dribbling urine stream. Treatment involves cystoscopic valve ablation (destroying the valves through a scope). Long-term kidney and bladder function monitoring is essential, as PUV can affect kidney development.
Key takeaways
- Posterior urethral valves (PUV) are abnormal folds of tissue in the urethra of boys that block the flow of urine out of the bladder. PUV is the most common cause of lower urinary tract obstruction in male newborns. It is often detected on prenatal ultrasound when bilateral hydronephrosis (swelling of both kidneys) and a distended bladder are seen. After birth, boys may have a weak or dribbling urine stream. Treatment involves cystoscopic valve ablation (destroying the valves through a scope). Long-term kidney and bladder function monitoring is essential, as PUV can affect kidney development.
- Usually normal when: PUV was diagnosed and your baby has had successful valve ablation with good urine output
- Call your doctor if: Your baby has significantly decreased urine output or no urine output, which may indicate obstruction
- Varies by age — see the age-by-age breakdown below
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What Parents Should Know
According to NIH, AAP, Children's Hospital guidelines, posterior urethral valves (PUV) are abnormal folds of tissue in the urethra of boys that block the flow of urine out of the bladder. PUV is the most common cause of lower urinary tract obstruction in male newborns. It is often detected on prenatal ultrasound when bilateral hydronephrosis (swelling of both kidneys) and a distended bladder are seen. After birth, boys may have a weak or dribbling urine stream. Treatment involves cystoscopic valve ablation (destroying the valves through a scope). Long-term kidney and bladder function monitoring is essential, as PUV can affect kidney development. At Prenatal, pUV is often suspected on prenatal ultrasound when bilateral hydronephrosis (dilated kidneys), a thick-walled distended bladder, and a dilated posterior urethra ("keyhole sign") are seen. Oligohydramnios (low amniotic fluid) can occur in severe cases because fetal urine contributes to amniotic fluid. Severe cases may be associated with lung underdevelopment (pulmonary hypoplasia) due to reduced amniotic fluid. Fetal intervention (vesicoamniotic shunting) may be considered in severe cases. Delivery is planned at a center with pediatric urology and NICU capabilities. It is generally considered normal when pUV was diagnosed and your baby has had successful valve ablation with good urine output. However, you should contact your pediatrician promptly if your baby has significantly decreased urine output or no urine output, which may indicate obstruction.
Normal vs. Concerning
When to Seek Immediate Care
- Your baby has significantly decreased urine output or no urine output, which may indicate obstruction
- Your baby has a fever with foul-smelling urine, which could indicate a urinary tract infection requiring urgent treatment to protect kidney function
- Your baby is irritable, not feeding well, and has a distended abdomen
- Your baby appears increasingly unwell with vomiting, lethargy, or poor feeding, which may indicate worsening kidney function
- A prenatal ultrasound shows severely dilated kidneys, distended bladder, and very low amniotic fluid - discuss urgently with your maternal-fetal medicine specialist
By Age
What to expect by age
Prenatal
PUV is often suspected on prenatal ultrasound when bilateral hydronephrosis (dilated kidneys), a thick-walled distended bladder, and a dilated posterior urethra ("keyhole sign") are seen. Oligohydramnios (low amniotic fluid) can occur in severe cases because fetal urine contributes to amniotic fluid. Severe cases may be associated with lung underdevelopment (pulmonary hypoplasia) due to reduced amniotic fluid. Fetal intervention (vesicoamniotic shunting) may be considered in severe cases. Delivery is planned at a center with pediatric urology and NICU capabilities.
0-1 week
After birth, a catheter is placed in the bladder to drain urine and relieve the obstruction. Blood tests assess kidney function (creatinine). A voiding cystourethrogram (VCUG) and renal ultrasound confirm the diagnosis and evaluate the kidneys and bladder. Once the baby is stable, cystoscopic valve ablation is performed - a small scope is passed through the urethra to visualize and destroy the obstructing valves. In very small or premature babies, a vesicostomy (opening in the bladder to the skin) may be performed instead, with valve ablation done later.
1-6 months
After valve ablation, follow-up ultrasounds monitor for improvement in hydronephrosis and kidney function. Blood tests track kidney function over time. Some degree of kidney damage may be irreversible, depending on how long and how severely the kidneys were affected before treatment. Vesicoureteral reflux (urine backing up to the kidneys) is common and may resolve on its own. Prophylactic antibiotics may be prescribed to prevent urinary tract infections.
6 months - 3 years
Ongoing monitoring of kidney function, bladder function, and growth is essential. Some boys develop "valve bladder syndrome" where the bladder remains thick-walled and does not empty well, even after the valves are removed. This can require clean intermittent catheterization (CIC) to help empty the bladder. Urinary tract infections should be treated promptly to protect kidney function. Toilet training may be delayed compared to peers.
3 years+
Long-term follow-up with pediatric urology and nephrology is important throughout childhood and into adulthood. About one-third of boys with PUV may develop chronic kidney disease over time. Bladder dysfunction may persist and require ongoing management. Regular monitoring of kidney function, blood pressure, and growth ensures any issues are caught early. With modern management, many boys with PUV live healthy, active lives.
What to Tell Your Pediatrician
- Describe when you first noticed has posterior urethral valves (puv) and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if your baby boy has a persistently weak or dribbling urine stream.
- Mention if you notice your baby strains or seems uncomfortable when urinating.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- PUV was diagnosed and your baby has had successful valve ablation with good urine output
- Your baby's kidney function is stable and being monitored by pediatric urology and nephrology
- Hydronephrosis is improving on follow-up ultrasounds
- Your baby is growing well and making adequate wet diapers
- Your child is being followed long-term as recommended
- Your baby boy has a persistently weak or dribbling urine stream
- You notice your baby strains or seems uncomfortable when urinating
- Your child has recurrent urinary tract infections
- You have concerns about your child's bladder habits or toilet training progress
- Your baby has significantly decreased urine output or no urine output, which may indicate obstruction
- Your baby has a fever with foul-smelling urine, which could indicate a urinary tract infection requiring urgent treatment to protect kidney function
- Your baby is irritable, not feeding well, and has a distended abdomen
- Your baby appears increasingly unwell with vomiting, lethargy, or poor feeding, which may indicate worsening kidney function
- A prenatal ultrasound shows severely dilated kidneys, distended bladder, and very low amniotic fluid - discuss urgently with your maternal-fetal medicine specialist
What You Can Do at Home
- Keep track of when you notice has posterior urethral valves (puv) — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that pUV was diagnosed and your baby has had successful valve ablation with good urine output — this is generally within the range of normal.
- At Prenatal, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
- While monitoring at home, seek immediate care if your baby has significantly decreased urine output or no urine output, which may indicate obstruction.
Related Conditions
Signs of Hydrocephalus in Babies
Hydrocephalus occurs when cerebrospinal fluid accumulates in the brain ventricles, causing increased pressure. In babies, the most noticeable sign is rapidly increasing head circumference (head growing faster than expected). Other signs include a bulging or tense fontanelle, prominent scalp veins, downward gaze of the eyes ("sunsetting"), irritability, vomiting, and developmental delays. Treatment typically involves surgical placement of a shunt or endoscopic third ventriculostomy to drain excess fluid.
Signs of a UTI in Babies
UTIs (urinary tract infections) in babies can be tricky to spot because symptoms are often vague - fever without other cold symptoms, fussiness, poor feeding, or foul-smelling urine. If your baby has unexplained fever, especially if under 3 months, your pediatrician may test for a UTI. UTIs need antibiotic treatment to prevent kidney damage.
Related Resources
Frequently asked questions
Is has posterior urethral valves (puv) normal?
When should I call the doctor about has posterior urethral valves (puv)?
When is has posterior urethral valves (puv) normal?
What causes has posterior urethral valves (puv)?
What should I mention to my pediatrician about has posterior urethral valves (puv)?
Is has posterior urethral valves (puv) normal at Prenatal?
Is has posterior urethral valves (puv) normal at 0-1 week?
Should I go to the ER for has posterior urethral valves (puv)?
Does has posterior urethral valves (puv) go away on its own?
References
- [1]National Institutes of Health. Posterior Urethral Valves. MedlinePlus Medical Encyclopedia, 2024. NIH
- [2]Urology Care Foundation. Posterior Urethral Valves. American Urological Association, 2024. AAP
- [3]Children's Hospital of Philadelphia. Posterior Urethral Valves. Children's Hospital
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss My Baby Has Posterior Urethral Valves (PUV).
Things to mention
- Describe when you first noticed has posterior urethral valves (puv) and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if your baby boy has a persistently weak or dribbling urine stream.
- Mention if you notice your baby strains or seems uncomfortable when urinating.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- Your baby boy has a persistently weak or dribbling urine stream
- You notice your baby strains or seems uncomfortable when urinating
- Your child has recurrent urinary tract infections
Urgent signs to report immediately
- Your baby has significantly decreased urine output or no urine output, which may indicate obstruction
- Your baby has a fever with foul-smelling urine, which could indicate a urinary tract infection requiring urgent treatment to protect kidney function
- Your baby is irritable, not feeding well, and has a distended abdomen
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
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Related Resources
Bottom line
Most cases of has posterior urethral valves (puv) are normal. Talk to your pediatrician if your baby has significantly decreased urine output or no urine output, which may indicate obstruction.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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Related Medical Concerns
Signs of Hydrocephalus in Babies
Hydrocephalus occurs when cerebrospinal fluid accumulates in the brain ventricles, causing increased pressure. In babies, the most noticeable sign is rapidly increasing head circumference (head growing faster than expected). Other signs include a bulging or tense fontanelle, prominent scalp veins, downward gaze of the eyes ("sunsetting"), irritability, vomiting, and developmental delays. Treatment typically involves surgical placement of a shunt or endoscopic third ventriculostomy to drain excess fluid.
Signs of a UTI in Babies
UTIs (urinary tract infections) in babies can be tricky to spot because symptoms are often vague - fever without other cold symptoms, fussiness, poor feeding, or foul-smelling urine. If your baby has unexplained fever, especially if under 3 months, your pediatrician may test for a UTI. UTIs need antibiotic treatment to prevent kidney damage.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.
Adrenoleukodystrophy (ALD) in Babies
X-linked adrenoleukodystrophy (X-ALD) is a genetic disorder affecting about 1 in 17,000 newborns, caused by mutations in the ABCD1 gene on the X chromosome. It primarily affects boys and impairs the breakdown of very long-chain fatty acids (VLCFAs), which accumulate and damage the myelin sheath in the brain and the adrenal glands. The most severe form, cerebral ALD, typically affects boys between ages 4-10 with rapid neurological decline. Newborn screening now enables early detection, and hematopoietic stem cell transplant or gene therapy performed before significant brain involvement can be life-saving.