**1. Introduction**

Hydrops fetalis or fetal hydrops is an abnormal fluid collection in two or more fetal compartments. This includes skin edema (>5 mm), ascites, pleural, and pericardial effusion. In some, this may be associated with the placental edema (placental thickness > 4 cm in the second trimester and >6 mm in the third trimester) [1] and polyhydramnios [2].

Hydrops fetalis is a serious fetal condition usually identified by ultrasound examination. Very rarely, subtle collection of fluid may be missed on ultrasound scan. Historically, hydrops fetalis was due to rhesus alloimmunisation, especially prior to prophylactic anti-D administration in the developed countries, although this may not be the case in many developing countries.
