Hydrops

An abnormal, excessive accumulation of watery fluid within the tissues, cells, or body cavities, producing localized or generalized edema. In obstetrics, it often refers to hydrops fetalis, defined sonographically by abnormal fluid collections in two or more fetal compartments (skin, pleura, pericardium, peritoneum). Possible causes of non-immune hydrops fetalis are heart failure, fetal anemia, chromosomal disorders, and twin pregnancy. Immune-mediated fetal hydrops is caused by blood-type incompatibility between the mother and the fetus. In adults, fluid retention leading to hydrops typically points to heart failure, liver cirrhosis, kidney failure, and lymphedema.