<prompt> 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:b-hCGPAPP-ANTAll of the above  <response>: Ans. is a, i.e. b-hCGRef. Fernando Arias 4e, 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. 