This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematological Disorders, Subject name: Gynaecology & Obstetrics
All predisposes to isoimmunisation in a Rh-ve female except. 
Select and explain. 
A. Advaned maternal age, B. Antepartum haemorrhage, C. Caesarian section, D. Postdated pregnancy
A: Advaned maternal age
Answer: A: Advaned maternal age 
Explanation: Ans. is 'a' i.e. Advanced maternal age Following are the conditions predisposing to isoimmunization in Rh-ve femaleabortionchorionic villous samplingamniocentesisantepartum Haemorrhage attempted versioncaesarian section*manual removal of placenta Recent studies state that there is continuous feto-maternal bleed occurring throughout normal pregnancies. So it is not advisable to go beyond the expected date of pregnancy. Hence postdated pregnancy is another risk-factor for isoimmunization. *