Fetal hydrops is defined as edema plus an accumulation of the fluid in at least one visceral cavity. It is not a defined disease but a morphologic description of underlying problem. It can be divided into two groups: immune and non-immune. Nowadays, there is significant reduction in the incidence of immune hydrops secondary to Rhesus disease, mostly by Immune Globulin prophylaxis. As well as that, the results of treatment by intrauterine transfusion significantly improves survival rate being as high as 90%. However, non-immune fetal hydrops still significantly contributes to fetal mortality and morbidity. Presentation of fetal hydrops can be through either routine ultrasound (US) screening program, detection of polyhydramnios, uterus larger than expected for the named gestational age ; or hydrops can be found during the investigation of maternal diabetes, pre-eclampsia and as a part of follow up of placental abruption. Ultrasound identification of fetal hydrops should initially focus on the presence or absence of fluid accumulation in thoracic, pleural or pericardial space, polyhydramnios, fetal edema, placental edema and alternations of the fetal umbilical vessels. After precise diagnosis mostly by US and color/pulsed Doppler as well as 3D US if available, fetal investigations include: 1. exclusion of accompanied anomalies ; 2 echocardiography ; 3. assessment of amniotic fluid volume ; 4. biophysical profile ; 5. invasive testing including: fetal karyotype, umbilical venous pressure, fetal full blood count, fetal hemoglobin electrophoresis and serologic test for specific antibodies (IgM class). The treatment of fetal hydrops is mostly related to the underlying cause. Immune fetal hydrops is usually managed by intrauterine fetal blood transfusion (IUFBT) and the results are promising. The survival rate of alloimmune fetal hydrops diagnosed before 24 weeks is up to 74% while if the diagnosis is made after 24 weeks survival rate can be up to 90%. In non-immune fetal anemia the results of IUFBT are not as good as in the cases of immune anemia. Survival rate is around 25% independently on the age of presentation.

Clinical medical sciences