The build up of fluid in the lungs increases the pressure in the lungs leading to vasoconstriction. The coupled vasoconstriction and pulmonary hypertension causes the right side of the heart to fail which in turn, increases the venous hydrostatic pressure in the body. The summation of these effects ultimately leads to peripheral edema and ascites. All in all, the left side failure of the heart will lead to pulmonary edema whereas right side failure will lead to peripheral edema and ascites. The non-immune form of hydrops fetalis has many causes including:
Iron deficiency anemia
Paroxysmal supraventricular tachycardia resulting in heart failure
Deficiency of the enzyme beta-glucuronidase. This enzyme deficiency is the cause of the lysosomal storage disease called mucopolysaccharidosis type VII. Congenital disorders of glycosylation
Parvovirus B19 (fifth disease) infection of the pregnant woman (most common cause)
Cytomegalovirus in mother
Congenital pulmonary airway malformation (formerly called congenital cystic adenomatoid malformation)
Maternal syphilis and maternal diabetes mellitus
Alpha-thalassemia can also cause hydrops fetalis when all four of the genetic loci for α globin are deleted or affected by mutation. This is termed Hb Barts (consists of y-4 tetramers). Uncommonly, Niemann-Pick disease Type C (NPC) and Gaucher disease type 2 can present with hydrops fetalis. Turner syndrome
Tumors, the most common type of fetal tumor being teratoma, particularly a sacrococcygeal teratoma.
Fetal hydrothorax, chylothorax, or large pleural effusion associated with bronchopulmonary sequestration should be treated using a Fetal needle drainage of effusion or placement of thoracoamniotic shunt. This procedure can be performed prior to delivery if gestational age is advanced. Hydrops Fetalis resulting from fetal CPAM can be treated using either a fetal needle drainage of effusion or placement of thoracoamniotic shunt or a maternal administration of corticosteroids, betamethasone 12.5 mg IM q24 h × 2 doses or dexamethasone 6.25 mg IM q12 h × 4 doses. Therapy for hydrops fetalis derived from TTTS or TAPS requires laser ablation of placental anastomoses or selective termination. Therapy for hydrops fetalis derived from TRAPS requires percutaneous radio frequency ablation. See also
Mirror syndrome


== References ==