CD4 and hepatitis C virus infection: It is noteworthy that for most of the study years considered, IDUs were more likely than non-IDUs to be unmarried, to have unintended pregnancy, later initiation of or no prenatal care, preterm delivery, to receive HIV diagnosis in labor and delivery, to have hepatitis C, no immunologic and virologic monitoring, lower CD4 count, later or incomplete antiretroviral prophylaxis, higher rates of perinatal transmission and infant abandonment (Table 1).