Hydrops fetalis is a serious condition. It occurs when abnormal amounts of fluid build up in two or more body areas of a fetus or newborn. It is a symptom of underlying problems.

What is the cause of hydrops fetalis?

Immune hydrops is caused by an incompatibility of red blood cells between the mother and her unborn baby. That incompatibility leads to the destruction of a large number of the baby's red blood cells (also known as hemolytic disease).

What is hydrops fetalis?

Hydrops fetalis — or hydrops — is a condition in which large amounts of fluid build up in a baby's tissues and organs, causing extensive swelling (edema).