Atazanavir and lopinavir profile in pregnant women with HIV : tolerability, activity and pregnancy outcomes in an observational national study

Background: Atazanavir and lopinavir represent the main HIV protease inhibitors recommended in pregnancy, but comparative data in pregnant women are limited. Methods: Women from a national observational study, exposed in pregnancy to either atazanavir or lopinavir, were compared for glucose and lipid profiles, liver function tests, CD4 count, HIV RNA and main pregnancy outcomes. Statistical methods included univariate and multivariable analyses. Results: The study population included 428 pregnancies (lopinavir, 322; atazanavir, 106). The lopinavir group was characterized by higher rates of HIV diagnosis in pregnancy and treatment indication for maternal health, lower CD4 counts, higher HIV RNA levels, less frequent antiretroviral treatment at conception and shorter duration of drug exposure during pregnancy. No differences in pregnancy outcomes, glucose metabolism and weight gain were observed. The two groups also showed in a multivariable analysis similar odds for detectable HIV RNA in the third trimester (adjusted OR 0.85, 95% CI 0.35-2.10, P1/40.730). Total lipid levels were significantly higher in the lopinavir group (median values in the third trimester 239 versus 221 mg/dL for total cholesterol and 226 versus 181 mg/dL for triglycerides; P<0.001 for both comparisons) and bilirubin levels were significantly higher in the atazanavir group (1.53 versus 0.46 mg/dL, P<0.001). Conclusions: In this observational study atazanavir and lopinavir showed similar safety and activity in pregnancy, with no differences in the main pregnancy outcomes. Atazanavir usewas associated with a better lipid profile and with higher bilirubin levels. Overall, the study findings confirm that these two HIV protease inhibitors represent equally valid alternative options