True about indications for prevention of Rh isoimmunization :
**Core Concept**
Rh isoimmunization occurs when an Rh-negative mother is exposed to Rh-positive blood, leading to the production of antibodies against Rh-positive red blood cells. This can cause hemolytic disease in subsequent Rh-positive fetuses. Prevention of Rh isoimmunization is crucial to avoid this condition.
**Why the Correct Answer is Right**
The correct indication for prevention of Rh isoimmunization is when the mother is Rh-negative and the father is Rh-positive, or when there is a possibility of Rh-positive fetal blood entering the maternal circulation, such as during delivery, miscarriage, or abortion. This is because the mother's immune system may recognize the Rh-positive fetal blood as foreign and produce antibodies against it, leading to hemolytic disease in future pregnancies.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the prevention of Rh isoimmunization. While it is true that Rh isoimmunization can occur during pregnancy, this option does not specify a situation where the mother is at risk of developing antibodies against Rh-positive red blood cells.
**Option B:** This option is incorrect because Rh isoimmunization is not typically a concern in cases where the mother is already sensitized to Rh-positive blood, such as in cases of previous pregnancy with an Rh-positive fetus or previous blood transfusion with Rh-positive blood.
**Option C:** This option is not a specific indication for prevention of Rh isoimmunization. While routine testing for Rh status is important, this option does not specify a situation where the mother is at risk of developing antibodies against Rh-positive red blood cells.
**Clinical Pearl / High-Yield Fact**
Rh isoimmunization is a classic example of an immune-mediated condition that can be prevented with proper management. It is essential to identify Rh-negative mothers and provide them with Rh immune globulin (RhIg) during pregnancy and delivery to prevent the development of antibodies against Rh-positive red blood cells.
**Correct Answer: C. Routine testing of Rh status in all pregnant women.**