Clinical Data An analysis of 34 women who received PREZISTA®/ritonavir dosed at either 600 mg/100 mg twice daily or 800 mg/100 mg once daily in combination with a background regimen demonstrated that exposures to PREZISTA® and ritonavir were lower during pregnancy compared with the postpartum period, but were well-tolerated, and virologic responses were preserved throughout the treatment period in both arms.1,2 There were no reports of mother-to-child HIV transmission among the 29 women who continued therapy through delivery.2 Nor were there any new clinically relevant safety findings compared with the known safety profile of PREZISTA®/ritonavir in HIV-1 infected adults. 2In addition, based on prospective reports to the Antiretroviral Pregnancy Registry (APR) (through July 2015) of 532 live births following PREZISTA® exposure during pregnancy, there was no difference in rates of overall birth defects for PREZISTA®compared with the background rate for major birth defects in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program.2 The prevalence of birth defects was 2.7 percent (95% CI, 1.2-5.1) among infants exposed to PREZISTA®-containing regimens in the first trimester, and 1.5 percent (95% CI, 0.3-4.4) among exposed infants in the second or third trimester.2