Overview
Congenital primary megaureter, also called primary obstructive megaureter or congenital megaureter, is a condition present from birth in which one or both of the ureters — the tubes that carry urine from the kidneys to the bladder — are abnormally wide or dilated. The word 'primary' means the widening is caused by a problem in the ureter itself, not by a blockage elsewhere in the urinary tract. In many cases, there is a short segment at the lower end of the ureter that does not squeeze and relax properly, which prevents urine from flowing freely into the bladder. This can cause urine to back up and put pressure on the kidney. Many babies with congenital primary megaureter are diagnosed before birth through routine prenatal ultrasound, which shows a swollen ureter or kidney. Some children have no symptoms at all and the condition improves on its own as they grow. Others may develop urinary tract infections, pain in the side or back, blood in the urine, or kidney problems if the condition is not treated. Treatment depends on how severe the condition is. Mild cases are often watched carefully with regular imaging and may resolve without surgery. More serious cases may need a surgical procedure to repair or widen the narrow segment of the ureter so urine can drain properly. With early diagnosis and appropriate care, most children do very well and can protect their kidney function long-term.
Also known as:
Key symptoms:
Widened or swollen ureter seen on ultrasoundSwollen kidney (hydronephrosis) due to backed-up urineRepeated urinary tract infectionsPain or discomfort in the side, back, or abdomenBlood in the urine (pink, red, or brown urine)Fever without a clear cause, especially in infantsNausea or vomitingPoor weight gain or feeding problems in infantsFrequent or painful urinationHigh blood pressure related to kidney stress
Clinical phenotype terms (10)— hover any for plain English
Multifactorial
Caused by a mix of several genes and environmental factors
Neonatal
Begins at or shortly after birth (first 4 weeks)
Treatments
No FDA-approved treatments are currently listed for Congenital primary megaureter.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Congenital primary megaureter at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for Congenital primary megaureter.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Congenital primary megaureter.
Community
No community posts yet. Be the first to share your experience with Congenital primary megaureter.
Start the conversation →Latest news about Congenital primary megaureter
No recent news articles for Congenital primary megaureter.
Follow this condition to be notified when news becomes available.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How severe is my child's megaureter, and is it affecting kidney function right now?,Does my child need surgery, or is watchful waiting the right approach?,How often will we need follow-up ultrasounds or kidney scans, and for how long?,Should my child take preventive antibiotics, and if so, for how long?,What signs should I watch for at home that would mean I need to go to the emergency room?,Could this condition affect my child's kidneys in the long term, and what can we do to protect kidney health?,Is there any chance this could affect future siblings or be passed on genetically?
Common questions about Congenital primary megaureter
What is Congenital primary megaureter?
Congenital primary megaureter, also called primary obstructive megaureter or congenital megaureter, is a condition present from birth in which one or both of the ureters — the tubes that carry urine from the kidneys to the bladder — are abnormally wide or dilated. The word 'primary' means the widening is caused by a problem in the ureter itself, not by a blockage elsewhere in the urinary tract. In many cases, there is a short segment at the lower end of the ureter that does not squeeze and relax properly, which prevents urine from flowing freely into the bladder. This can cause urine to back u
How is Congenital primary megaureter inherited?
Congenital primary megaureter follows a multifactorial inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Congenital primary megaureter typically begin?
Typical onset of Congenital primary megaureter is neonatal. Age of onset can vary across affected individuals.