When patients present in labor, zidovudine (ZDV) is given at 2 mg / kg IV for the first hour and then at 1 mg / kg / hour IV until delivery to women who have ≥ 1 of the following: Recent HIV plasma viral load > 1000 copies / mL Unknown HIV plasma viral load near delivery Are thought to have had incomplete adherence to ART Many experts now believe that IV ZDV is not required during labor for women receiving combination ART who have achieved HIV plasma viral loads < 50 copies / mL near delivery.