Exposure to antiretroviral agents during pregnancy does not alter bone status in infants

The use of combined antiretroviral agents during pregnancy is important to prevent mother-to-child transmission of human immunodeficiency virus (HIV). Antiretroviral treatment (ARV) is associated with reduced bone mass and altered bone metabolism in HIV-infected patients. There are no data regarding the effect of ARV exposure during pregnancy on newborns and infants. We therefore studied 38 subjects born from HIV-infected mothers, and we measured the speed-of-sound (SOS) at the tibia by quantitative ultrasonography (QUS) just after birth. QUS measurements at mid-tibia is easily performed in infants with the appropriate probe. Nevertheless, at this skeletal site only cortical bone is present, and therefore QUS measurements reflect the status of only one kind of bone tissue. We also measured bone alkaline phosphatase (BAP) and C-terminal telopeptide of type I collagen (CTX) in the cord blood as bone formation and resorption markers, respectively. SOS measurements were repeated at 4 and 12 months of age. As a control group we studied 94 subjects born from HIV-negative mothers. At birth the median (range) SOS of ARV-exposed neonates was 3006 (2870-3168) m/s, while that of control subjects was 3007 (2757-3311) m/s. The difference was not significant. BAP concentration of ARV-exposed was 103.6 (31.6-182.8) U/L, not different from that of control subjects (104.4 [43.2-227.2] U/L). CTX concentrations were 1.07 (0.26-2.8) ng/mL, and 1.38 (0.34-4.2) ng/mL in ARV-exposed and control subjects, respectively. SOS measurements at 4 months and 12 months of age were available for 17 ARV-exposed subjects and for 57 control subjects. SOS values changed significantly over time in both groups (F=6.1; P<0.0001). No differences were present between ARV-exposed and control subjects at 4 and 12 months. Our study suggests that ARV exposure during intrauterine life does not affect negatively bone metabolism and bone development, and that the changes occurring in bone QUS measurements during the first year of life in ARV-exposed subjects are similar to those occurring in healthy control infants.