Antiretroviral therapy at conception in pregnant women with HIV in Italy: wide range of variability and frequent exposure to contraindicated drugs.

Methods: Data from a large national surveillance study was used to describe antiretroviral regimens in pregnant women with HIV, with particular reference to the presence at conception of antiretroviral treatments contraindicated in pregnancy. Therapeutic changes during pregnancy were also analysed.
Results: Among 334 women on antiretroviral treatment at conception, less than half (42.4%) reported current pregnancy as planned. A large number of different regimens (80) was observed. All the regimens included at least one nucleoside or nucleotide reverse transcriptase inhibitor. Non-nucleoside reverse transcriptase inhibitors and protease inhibitors were present in similar proportions (39.2% and 40.7%, respectively). The most commonly used drugs were lamivudine (83.2% of regimens), zidovudine (50.0%), stavudine (d4T; 38.0%), nevirapine (25.7%), didanosine (ddl; 17.7%) and nelfinavir (17.7%). Treament with efavirenz (13.5% of regimens) and ddl+d4T (9.6%) was markedly frequent. Use of efavirenz at conception was associated with a subsequent treatment change during pregnancy (odds ratio [OR]: 13.2.; 95% confidence interval [CI]: 3.2-53.8, P < 0.001). A similar but less strong association was found for ddl (OR: 1.8; 95% CI: 1.03-3.25, P = 0.033), whereas being on nevirapine was associated with a lower risk (OR: 0.58; 95% CI: 0.38-0.81, P = 0.013).
Conclusions: Our data show that treatment at conception frequently represents the regimen previously selected for the treatment of the non-pregnant woman. The observed rates of exposure to contraindicated treatment should lead prescribing physicians to consider in HIV-positive women therapeutic choices that take into account the likelihood of an unplanned pregnancy. Such an approach is likely to reduce not only unintended exposures to contraindicated drugs, but also therapeutic changes during pregnancy.