Anti-La\SSB autoantibody
This antibody attacks the ribonucleoprotein La48 on the surface of the fetal cardiomyocytes, the links between this autoantibody and autoimmune CHB are less strong than the anti-Ro autoantibody and it usually accompanies it in the majority of cases.Although the autoimmune CHB has a relatively high mortality and morbidity rates, the chance of kids from -mothers positive to anti-Ro\SSA and/or anti-La\SSB antibodies- to suffer from CHB is only around 1-5%, which suggests the existence of other factors to influence the disease such as genetic and environmental factors. Other autoantibodies
Several autoantibodies were suggested to have links with the autoimmune CHB, mainly the ones associated with the different autoimmune diseases that are common among women (such as the antibodies associated with Systemic lupus erythematosus (SLE), Rheumatoid arthritis, Progressive systemic sclerosis (PSS), and Mixed connective tissue disease). However, the role of these autoantibodies was not studied comprehensively.Also, some antigens of the fetal heart tissue (apart from the "Ro" and the "La") were studied, but no clear link with the autoimmune CHB was proven. Congenital cardiac structural abnormalities
The presence of a cardiac structural abnormality is a major determination of the outcome of CHB. Its existence affects the conduction system of the heart and increases the mortality rate and the need for pace-maker implantation.The cardiac structural diseases that are usually associated with the congenital heart block include the left atrial isomerism with or without atrioventricular septal defect.
In the event of a pregnancy where the fetus has the Rh-D blood antigen and the mother does not, the mothers 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 mothers immune system launches an attack, via IgG, against the infants 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 (Rho(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 (Rho(D) Immune Globulin). 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.