Unknown The least amount of fetal Rh+ve blood needed to cause isoimmunization in a Rh negative mother is – A 0.1 ml B 0.01 ml C 0.001 ml D 10 ml 💡 Explanation The least amount of fetal Rh+ve blood needed to cause isoimmunization in a Rh negative mother is - ✓ Correct Answer: A. 0.1 ml