Overview
Non-immune hydrops fetalis (NIHF) is a serious condition that occurs before or shortly after birth, where abnormal fluid builds up in two or more body areas of the baby. These areas can include the space around the lungs (pleural effusion), the belly (ascites), the area around the heart (pericardial effusion), and the skin (generalized swelling or edema). The term 'non-immune' means this fluid buildup is NOT caused by blood type incompatibility between the mother and baby (which would be called immune hydrops). Instead, NIHF can result from a wide range of underlying causes, including genetic conditions, heart defects, infections, metabolic disorders, chromosomal abnormalities, lymphatic malformations, and problems with the placenta or umbilical cord. NIHF is often detected during pregnancy through routine ultrasound, which may show excess fluid in the baby's body cavities and generalized swelling. The condition is serious and can be life-threatening. In many cases, the underlying cause determines how severe the condition is and what treatment options are available. Some causes are treatable if identified early — for example, certain heart rhythm problems can be treated with medication given to the mother, and some infections or anemias can be addressed before birth. However, in many cases, the prognosis remains guarded. Treatment focuses on identifying and addressing the root cause, draining excess fluid when needed, and providing supportive care in a neonatal intensive care unit after delivery. Advances in prenatal diagnosis and fetal therapy have improved outcomes for some babies, but NIHF remains a major challenge in perinatal medicine.
Key symptoms:
Severe swelling of the baby's body (edema)Fluid buildup around the lungsFluid buildup in the belly (ascites)Fluid buildup around the heartThickened placentaExcess amniotic fluid (polyhydramnios)Difficulty breathing at birthPale or bluish skin colorEnlarged liver or spleenSevere anemiaLow heart rate or abnormal heart rhythmPoor feeding after birthLow blood protein levelsSwollen scalp in the baby
Variable
Can be inherited in different ways depending on the underlying gene
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
1 eventUniversity of California, San Francisco — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Non-immune hydrops fetalis.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →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 Non-immune hydrops fetalis.
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Questions for your doctor
Bring these to your next appointment
- Q1.What is the underlying cause of the hydrops in my baby, and has it been identified?,What additional testing should be done to find the cause if it is not yet known?,Are there any treatments that can be started before birth to help my baby?,What is the expected prognosis based on the specific cause in our case?,What will my baby need immediately after delivery, and should I deliver at a specialized center?,What is the chance this could happen again in a future pregnancy, and should we have genetic counseling?,What long-term follow-up and specialist care will my child need after leaving the hospital?
Common questions about Non-immune hydrops fetalis
What is Non-immune hydrops fetalis?
Non-immune hydrops fetalis (NIHF) is a serious condition that occurs before or shortly after birth, where abnormal fluid builds up in two or more body areas of the baby. These areas can include the space around the lungs (pleural effusion), the belly (ascites), the area around the heart (pericardial effusion), and the skin (generalized swelling or edema). The term 'non-immune' means this fluid buildup is NOT caused by blood type incompatibility between the mother and baby (which would be called immune hydrops). Instead, NIHF can result from a wide range of underlying causes, including genetic
At what age does Non-immune hydrops fetalis typically begin?
Typical onset of Non-immune hydrops fetalis is neonatal. Age of onset can vary across affected individuals.
Are there clinical trials for Non-immune hydrops fetalis?
Yes — 1 recruiting clinical trial is currently listed for Non-immune hydrops fetalis on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Non-immune hydrops fetalis?
2 specialists and care centers treating Non-immune hydrops fetalis are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.