, a type of
hemolytic disease of the newborn, suffering from hydrops fetalis. The infant did not survive. Hydrops fetalis usually stems from fetal
anemia, when the heart needs to pump a much greater volume of blood to deliver the same amount of oxygen. This anemia can have either an immune or non-immune cause. Non-immune hydrops can also be unrelated to anemia, for example if a fetal
tumor or
congenital pulmonary airway malformation increases the demand for blood flow. The increased demand for cardiac output leads to heart failure, and corresponding edema.
Immune pathophysiology Erythroblastosis fetalis, also known as
Rh disease, is one possible immune cause of hydrops fetalis (next to Anti-Kell). Rh disease is a hemolytic disease of newborns. Pregnant mothers do not always have the same blood type as their child. During birth or throughout the pregnancy, the mother may be exposed to the infant's blood. In the event of a pregnancy where the fetus has the Rh-D blood antigen and the mother does not, the mother's immune system will respond to the red blood cells as foreign and create
antibodies against the Rh-D antigen on the fetal blood cells. Rh disease develops in the event of a second pregnancy where the mother's immune system launches an attack, via
IgG, against the infant's Rh-D positive blood cells. The immune response results in hemolysis of fetal red blood cells causing severe anemia. Hemolysis caused by the Rh incompatibility, causes
extramedullary hematopoiesis in the fetal liver and bone marrow. The push to make more erythroblasts to help compensate with the hemolysis over works the liver causing hepatomegaly. The resulting liver dysfunction decreases
albumin output which in turn decreases
oncotic pressure. Consequentially, the decrease in pressure results in overall peripheral edema and ascites. Rh disease is currently an uncommon cause of immune-mediated hydrops fetalis. Due to preventative methods developed in the 1970s, the incidence of Rh disease has markedly declined. Rh disease can be prevented by administration of anti-D IgG (
Rh(D) immune globulin) injections to RhD-negative mothers during pregnancy and/or within 72 hours of the delivery. However, a small percentage of pregnant mothers are still susceptible to Rh disease even after receiving anti-D IgG.
Non-immune pathophysiology Severe anemia leads to
hyperdynamic circulation, which means high-output cardiac failure causes the blood to circulate rapidly. The excessive pumping of blood causes the left side of the heart to fail leading to pulmonary edema. 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. •
Twin-twin transfusion syndrome (TTTS) in
pregnancies in which twins share a single placenta (hydrops affects the recipient twin) •
Twin anemia-polycythemia sequence (TAPS) •
Twin reversed arterial perfusion sequence (TRAPS) • Maternal
hyperthyroidism • Fetal cardiac defects and skeletal defects •
Noonan syndrome •
Mirror syndrome, in which fetal and placental hydrops develops in association with maternal
preeclampsia, edema and hypertension •
Down syndrome ==Diagnosis==