This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Which type of Hb is not affected by Rh isoimmunisation: 
Select and explain. 
A. Anti C, B. Anti E, C. Anti lewis, D. Anti D
C: Anti lewis
Answer: C: Anti lewis 
Explanation: “An antigen frequently found in routine antenatal screening is the Lewis group (Lea and Leb). The Lewis antigens do not cause erythroblastosis fetalis and differ from all of the other red cell antigens in that they are not synthesized in the red cell membrane but are absorbed into it.”
Fernando Arias 2/e, p 116