Understanding Lower Urinary Tract Obstruction (LUTO)
What is LUTO?
Lower urinary tract obstruction (LUTO) is a condition in which there is a blockage in a fetus’s urinary tract, preventing normal drainage of urine from the bladder. This can lead to:
- Bladder enlargement
- Kidney damage
- Reduced amniotic fluid (oligohydramnios), which is critical for lung development
- Underdeveloped lungs
LUTO varies widely in severity. Some cases are mild and manageable, while others can significantly affect fetal and neonatal outcomes.
(Pic: Illustration of a normal urinary tract: Kidneys, ureters, bladder and urethra)
What is LUTO?
The most common causes of LUTO include:
- Posterior urethral valves (PUV): The most frequent cause in male fetuses; abnormal tissue obstructs urine flow in the urethra (tube that drains the bladder)
- Urethral atresia: Complete absence or closure of the urethra
- Urethral stenosis: Narrowing of the urethra
- Prune belly syndrome: A complex condition involving urinary tract dilation, weak abdominal muscles, and undescended testes
- Other rare anomalies affecting bladder or urethral development
(Pic: Illustration with arrow demonstrating posterior urethral valves in a male fetus)
Fetal Center: the first step in care
Multidisciplinary Evaluation: meet with MFM specialist, pediatric nephrologist, pediatric urologist, neonatologist, and other experts who may care for your baby
Comprehensive Imaging: detailed ultrasounds and other tests when indicated to assess your baby's condition and help plan treatment
Coordinated Delivery Planning: our team works to ensure your baby receives immediate specialized care at birth if needed
How is LUTO evaluated?
LUTO is typically found on prenatal ultrasound with the following findings:
- Enlarged bladder (megacystis)
- Dilated ureters and kidneys (hydronephrosis)
- Thickened bladder wall
- Low amniotic fluid levels
Further evaluation at our fetal center may include:
- Detailed fetal ultrasound: to assess anatomy and severity
- Fetal echocardiogram: to evaluate the heart for structure and function
- Fetal urine sampling (vesicocentesis): Helps assess kidney function and prognosis
- Genetic testing: to evaluate for chromosomal abnormalities
- MRI (in select cases): for additional anatomical detail
(Pic: fetal ultrasound with arrow demonstrating enlarged bladder)
Is there prenatal treatment of LUTO?
Management depends on severity and overall prognosis.
Expectant Management
- Close monitoring with serial ultrasounds
- Appropriate for milder cases or when intervention is not indicated in the fetus
Fetal Intervention (in select cases)
These are considered when there is severe obstruction, poor amniotic fluid, and evidence of potentially salvageable kidney function:
- Vesicoamniotic shunt placement: A small tube is inserted to drain urine from the fetal bladder into the amniotic sac, helping restore fluid levels and support lung development
- These procedures carry risks, including preterm labor, infection, and shunt complications, and are only offered after careful evaluation.
(Pic: fetal ultrasound guided vesicoamniotic shunt placement)
Where should a child with LUTO be delivered?
Babies with LUTO should be delivered at our center with a neonatal intensive care unit (NICU) that specializes in the care of these infants and where a nephrologist (kidney doctor) and other pediatric specialists can immediately evaluate your child. The neonatologist is a specially trained pediatrician that will manage your baby’s medications, feeding, and daily needs while in the NICU.
How is a child with LUTO initially stabilized?
Many of these children will require placement of a tube into the airway (endotracheal tube) and placement on a ventilator to assist with breathing. Additionally a tube placed through the mouth (oral gastric or OG) into the stomach to remove contents to prevent stomach and bowel dilation. Eventually, this tube will be replaced with a feeding tube through the nose (NG tube) to help feed the child..
Your baby will receive fluids and antibiotics through a special IV called a PICC line, initially through the umbilical cord, then placed in one of the limbs. Because the child will not be initially allowed to eat, they will also receive nutrition through the PICC line called TPN, or total parenteral nutrition. TPN contains protein, fat, sugar, vitamins, and minerals and will meet all your baby’s nutritional needs.
Depending on the severity of kidney disease, some will require placement of a special catheter in a large vein, usually in the neck, to allow for hemodialysis to begin (HD catheter). This helps the team manage the child's electrolytes and to eliminate waste the body usually excretes in the urine.
(Pic: Illustration of a child with LUTO treated in the NICU)
How is LUTO treated after initial stabilization?
Definitive Treatment depends on the underlying cause:
- Posterior urethral valves: Endoscopic valve ablation
- Severe obstruction: Temporary urinary diversion (e.g., vesicostomy)
- Long-term management: May include medications, catheterization, or reconstructive surgery
The NICU, Nephrology, and Urology teams will work together to come up with the best plan to treat the baby based on kidney function and other studies.
If long-term dialysis is needed, a special dialysis catheter can be placed in the abdomen, to allow for peritoneal dialysis to occur at home after the child is discharged from the hospital (PD catheter).
(Pic: Illustration of child with LUTO that requires PD catheter placement)
Long-term Kidney Care
Children with LUTO often require ongoing care to monitor:
- Kidney function
- Bladder function
- Growth and development
Some children may develop chronic kidney disease and require specialized care by Nephrology and Urology.
- Children that require kidney transplant typically won't qualify until 18 - 24 months of age to accommodate an adult sized kidney.
Follow the link below to meet the Kidney Care team at Primary Children's Hospital
