Hydrops fetalis, or hydrops, is a condition that occurs when large amounts of fluid build up in a baby’s tissues and organs causing extreme swelling. Patients with hydrops fetalis are treated through the Thalassemia Program at  Dana-Farber/Boston Children's Cancer and Blood Disorders Center, an integrated pediatric hematology and oncology partnership between Dana-Farber Cancer Institute and Boston Children’s Hospital.

• Hydrops fetalis can be life-threatening.
• There are two types of hydrops fetalis, immune and non-immune.
• Immune hydrops fetalis is no longer common in the United States.
• Non-immune hydrops fetalis occurs in one of every 1,000 births in the United States.
• Hydrops fetalis can be diagnosed before or after birth.
• Treatment of hydrops fetalis depends on its cause.
• About half of unborn babies with hydrops fetalis do not survive.