Chapter 18 - Section 18.3 - Blood Types - Apply What You Know - Page 689: 1

Hemolytic Disease of the Newborn (HDN), also known as erythroblastosis fetalis, is a condition that occurs when there is an incompatibility between the blood types of a mother and her fetus. One common scenario is when a mother is Rh-negative (lacks the Rh antigen) and her baby is Rh-positive (has the Rh antigen inherited from the father). This can lead to an immune response in the mother's body against the Rh-positive blood cells of the fetus. This immune response can cause various effects, including jaundice and an enlarged spleen in the newborn. Here's an explanation of these effects: 1. **Jaundice (Hyperbilirubinemia):** - Jaundice refers to the yellowing of the skin and eyes due to an excess of bilirubin, a yellow pigment that is a breakdown product of hemoglobin from red blood cells. - In HDN, the mother's immune system produces antibodies against the Rh-positive red blood cells of the fetus. These antibodies can cross the placenta and attack the fetal red blood cells, leading to their destruction (hemolysis). - As a result of the increased breakdown of red blood cells, there is an elevated level of bilirubin in the bloodstream. - The liver of a newborn may not be fully developed and efficient in processing and eliminating bilirubin, causing it to accumulate in the blood and leading to the characteristic yellow discoloration of the skin and eyes seen in jaundice. 2. **Enlarged Spleen (Splenomegaly):** - The spleen is an organ responsible for filtering the blood and removing old or damaged red blood cells, among other functions. - In HDN, the immune response against the fetal red blood cells leads to their premature destruction, primarily in the bloodstream but also in organs like the spleen. - As the spleen works to clear the damaged red blood cells, it can become enlarged due to increased workload and cell turnover. - Splenomegaly can contribute to the anemia associated with HDN, as the accelerated destruction of red blood cells leads to a reduced number of circulating red blood cells. Both jaundice and an enlarged spleen are signs of the immune-mediated destruction of fetal red blood cells in HDN. While jaundice is a result of the accumulation of bilirubin due to increased hemolysis, splenomegaly is a response to the increased workload of removing damaged red blood cells from the circulation. Management and treatment of HDN may involve interventions to reduce the severity of these effects, such as phototherapy for jaundice and addressing the anemia associated with splenomegaly.

Hemolytic Disease of the Newborn (HDN), also known as erythroblastosis fetalis, is a condition that occurs when there is an incompatibility between the blood types of a mother and her fetus. One common scenario is when a mother is Rh-negative (lacks the Rh antigen) and her baby is Rh-positive (has the Rh antigen inherited from the father). This can lead to an immune response in the mother's body against the Rh-positive blood cells of the fetus. This immune response can cause various effects, including jaundice and an enlarged spleen in the newborn. Here's an explanation of these effects: 1. **Jaundice (Hyperbilirubinemia):** - Jaundice refers to the yellowing of the skin and eyes due to an excess of bilirubin, a yellow pigment that is a breakdown product of hemoglobin from red blood cells. - In HDN, the mother's immune system produces antibodies against the Rh-positive red blood cells of the fetus. These antibodies can cross the placenta and attack the fetal red blood cells, leading to their destruction (hemolysis). - As a result of the increased breakdown of red blood cells, there is an elevated level of bilirubin in the bloodstream. - The liver of a newborn may not be fully developed and efficient in processing and eliminating bilirubin, causing it to accumulate in the blood and leading to the characteristic yellow discoloration of the skin and eyes seen in jaundice. 2. **Enlarged Spleen (Splenomegaly):** - The spleen is an organ responsible for filtering the blood and removing old or damaged red blood cells, among other functions. - In HDN, the immune response against the fetal red blood cells leads to their premature destruction, primarily in the bloodstream but also in organs like the spleen. - As the spleen works to clear the damaged red blood cells, it can become enlarged due to increased workload and cell turnover. - Splenomegaly can contribute to the anemia associated with HDN, as the accelerated destruction of red blood cells leads to a reduced number of circulating red blood cells. Both jaundice and an enlarged spleen are signs of the immune-mediated destruction of fetal red blood cells in HDN. While jaundice is a result of the accumulation of bilirubin due to increased hemolysis, splenomegaly is a response to the increased workload of removing damaged red blood cells from the circulation. Management and treatment of HDN may involve interventions to reduce the severity of these effects, such as phototherapy for jaundice and addressing the anemia associated with splenomegaly.