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: Medicine
[{'content': 'True about HIV in pregnancy - \nSelect and explain. \nA. Perinatal transmission common, B. LSCS increases chances of transmission significantly, C. Less than 5% chance of transmission, D. Pregnancy predisposes to HIV infection', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mother to infant transmission is the major cause of pediatric AIDS.\nInfected mothers can transmit the infection to their offspring by three routes.\n\ni) In utero by transplacental spread\nii)During delivery through an infected birth canal\niii) After birth by ingestion of breast milk.\n\nOf these, transmission during birth (intrapartum) and in the immediate period thereafter (peripartum) is considered to be the most common mode.\nThe reported transmission rate varies from 7% to 49%.\nHigher risk of transmission is associated with high maternal viral load and low CD4+ T-cell count as well as chorioamnionitis.\nCurrently, with antiretroviral therapy given to infected pregnant women, the mother to child transmission has been reduced to very low levels.\nZidovudine alone or in combination with lamivudine given to mother during the last few weeks of pregnancy or even only during labour and delivery and to the infant for a week or less reduces the transmission by 50%.\nSingle dose nevirapine is also an effective prophylactic antiretroviral regimen.\nIt is of particular relevance to low to mid income nations because of the low cost.\nThere is a significant decrease in the risk of HIV transmission with an elective cesarean.\nLSCS reduces the risk because during this procedure the intrapartum period which accounts for a significant proportion of transmission is by-passed.\nPregnancy does not predispose to HIV infection.', 'role': 'assistant'}]