Hydrops fetalis is a serious condition. It occurs when abnormal amounts of fluid buildup in two or more body areas of a fetus or newborn. It is a symptom of underlying problems.
There are two types of hydrops fetalis -- immune and nonimmune. The type depends on the cause of the abnormal fluid.
- Immune hydrops fetalis is a complication of a severe form of Rh incompatibility. This is a condition in which mother who has Rh negative blood type makes antibodies to her baby’s Rh positive blood cells, and the antibodies cross the placenta. Rh incompatibility causes a large number of red blood cells in the fetus to be destroyed. This leads to problems including total body swelling. Severe swelling can interfere with how the body organs work.
- Nonimmune hydrops fetalis occurs when a disease or medical condition upsets the body's ability to manage fluid. There are three main causes for this type: heart or lung problems, severe anemia (e.g. from thalassemia or infections), and genetic or developmental problems, including Turner syndrome.
The number of babies who develop immune hydrops fetalis has dropped due to a medicine called RhoGAM. This drug is used to treat pregnant mothers at risk for Rh incompatibility.
Symptoms depend on the severity of the condition. Mild forms may cause:
More severe forms may cause:
Exams and Tests
An ultrasound done during pregnancy may show:
- High amounts of amniotic fluid
- Abnormally large placenta
- Fluid that leads to swelling in the unborn baby's belly area and organs, including the liver, spleen, heart, or lung area
An amniocentesis and frequent ultrasounds will be done to determine the severity of the condition.
Treatment depends on the cause. During pregnancy, treatment may include:
- Medicine to cause early labor and delivery of the baby
- Early cesarean delivery if condition gets worse
- Giving blood to the baby while still in the womb (intrauterine fetal blood transfusion)
Treatment for a newborn may include:
- Direct transfusion of red blood cells that match the infant’s blood type. An exchange transfusion to rid the baby's body of the substances that are destroying the red blood cells is also done.
- Removing extra fluid from around the lungs and belly area with a needle
- Medicines to control heart failure and help the kidneys remove extra fluids
- Methods to help the baby breathe, such as a breathing machine
Hydrops fetalis often results in death of the infant shortly before or after delivery. The risk is highest for babies born very early or who are ill at birth.
Brain damage called kernicterus may occur.
Rh incompatibility can be prevented if the mother takes a medicine called RhoGAM during and after pregnancy.
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Bellini C, Hennekam RCM, Fulcheri E, Rutigliani M, Morcaldi G, Boccardo F, Bonioli E. 2009. Etiology of nonimmune hydrops fetalis: A systematic review. Am J Med Genet Part A 149A:844–851.
Kumar V, Abbas AK, Aster JC, Fausto N, Perkins JA. Robbins and Cotran Pathologic Basis of Disease. 8th ed. Chapters 10 and 14 Philadelphia, Pa: WB Saunders, an imprint of Elsevier, Inc.; 2009.