<prompt> HIV treatment in pregnancyAfter diagnosis till lifelongAfter 1st trimester till lifelongAfter diagnosis till puerperiumAfter pregnancy till lifelong  <response>: Ref. DC Duttas Textbook of Obstetrics. Pg 352 Regardless of HIV viral load and CD4 count, all HIV infected pregnant women should be offered antiretroviral therapy ART after diagnosis till lifelong to reduce perinatal transmissionART should focus on reduction of perinatal transmission and treatment of maternal HIV disease.It reduces perinatal transmission by several mechanisms , including lowering maternal antepartum viral load and pre exposure and post exposure prophylaxis of the infant.Therefore, for prevention of perinatal transmission of HIV ,combined antepartum, intrapartum, and infant antiretroviral prophylaxis is recommended . 