This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis in Obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'An HIV positive, 36 years old female on ART needs counseling. Which of the following 1st trimester markers of Down syndrome would be affected by HIV: \nSelect and explain. \nA. b-hCG, B. PAPP-A, C. NT, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is a, i.e. b-hCGRef. Fernando Arias 4/e, p 4In women with HIV:b-hCG levels in women who are HIV positive and are on treatment have been shown to have a lower value than women without HIV and those with HIV not receiving treatment. In contrast PAPP- A levels and NT are not affected by HIV status.', 'role': 'assistant'}]