This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical Illness Complicating Pregnancy, Subject name: Gynaecology & Obstetrics
Congenital Infection affecting the fetus with minimal teratogenic risk is: 
Select and explain. 
A. HIV, B. Rubella, C. Varicella, D. CMV
A: HIV
Answer: A: HIV 
Explanation: * HIV is not teratogenic * CMV is the commonest cause of fetal & perinatal infection * No teratogenic effects - HIV, measles, influenza * Rubella is most teratogenic agent known