Summary

Fetal hydrops is a life-threatening condition defined as abnormal accumulation of fluid in two or more fetal compartments: ascites, pleural effusion, pericardial effusion, or generalized skin edema [1]. Fetal hydrops may also be associated with polyhydramnios and placental edema [2].

Based on pathophysiology results, fetal hydrops is classified as either immune or non-immune. The frequency of immune fetal hydrops has decreased dramatically since the development of Rh (D) immunization given to mothers at risk. Nonimmune hydrops fetalis (NIHF) accounts for almost 90% of cases [1]. The etiology of NIHF is further classified as cardiovascular (17–35%), chromosomal (7–16%), hematologic (4–12%), infectious (5–7%), and unknown (15–25%). Inborn errors of metabolism account for only 1–2% of NIHF cases [1]. NIHF is commonly progressive. Complete resolution of NIHF before birth is rare.