Neonatology Atlas

1.1 Hydrops

It is generalized subcutaneous edema in the neonate, usually accompanied by third space fluid accumulations e.g. ascites, pleural or pericardial effusions. It is caused by various immune/nonimmune causes.

Etiopathogenesis:

The pathogenesis of hydrops includes :

Elevated central venous pressure with cardiac output less than venous return,

Anemia resulting in high output cardiac failure,

Decreased lymphatic flow and colloid oncotic pressure,

Capillary leak.

1) Hematologic: Rh incompatility, homozygous ɑ-thalassemia, homozygous G6PD deficiency, twin-to-twin transfusion.

2) Cardiovascular: supraventricular tachycardia, Heart block, myocarditis, Ebstein anomaly.

3) Renal: renal vein thrombosis, renal hypoplasia4) Infection: Syphilis, rubella, Cytomegalovirus, herpes, adenovirus,

toxoplasmosis5) Pulmonary: diaphragmatic hernia, cystic adenomatoid malformations6) Placental: umbilical vein thrombosis, arteriovenous malformation7) Maternal conditions: diabetes, thyrotoxicosis8) Gastrointestinal: meconium peritonitis, in utero volvulus

9) Chromosomal: Turner syndrome, trisomy 13, 18, 21.10) Miscellaneous: Wilms tumour, neuroblastoma, Gaucher disease.

Diagnosis:

Antenatal 1) Maternal ultrasonography, blood type and coombs test, complete blood count

and RBC indices, haemoglobin electrophoresis, syphilis, TORCH titres.2) Fetal echocardiography, ultrasonography.3) Amniocentesis for karyotype, metabolic studies, fetoprotein, cultures and

polymerase chain reaction for infections and restriction endonucleases.4) Doppler ultrasonographic measurements of peak velocity of blood flow in the

fetal middle cerebral artery.5) Fetal blood sampling-percutaneous umbilical blood sampling: karyotype,

CBC, haemoglobin electrophoresis, cultures, PCR, DNA studies.

Neonatal: CBC, blood typing, coombs test, Chest x-rays, ultrasonographic studies of the head, heart and abdomen, examination of pleural and ascitic fluid, Liver Function tests, urinalysis.

Treatment:1. Intrauterine treatment in the form of fetal transfusion in isoimmune

haemolytic anemia or intrauterine paracentesis or thoracentesis.2. Fluid restriction (40-60 ml/kg/day as dextrose water) until edema is resolved.3. Virtually all infants with hydrops require mechanical ventilation.4. Chest tube drainage may be indicated if repeated thoracenteses cannot

control hydrothorax.5. Judicious use of diuretics is often helpful in reducing pulmonary edema. 6. If the haematocrit is < 30%, a partial exchange transfusion with 50 to 80

ml/kg packed RBCs should be performed to raise the haematocrit and increase oxygen-carrying capacity.

7. Ionotropic support may be required to improve cardiac output.

Prognosis: Reported survival rates for all foetuses diagnosed antenatally with Hydrops range from 12 to 24%. Higher survival rates have been reported in infants born alive, highest rates are still only 40% to 50%.