This study will evaluate the pharmacokinetic disposition of raltegravir in pregnant HIV-1 infected women. These results will be compared to pharmacokinetic data obtained following pregnancy as well as to studies previously carried out in nonpregnant women and male patients. By determining the disposition characteristics for this specific patient population, antiretroviral (ARV) dosing can be optimized during pregnancy. Appropriate dosing is necessary to minimize adverse effects, slow progression of disease, and further reduce the risk for vertical transmission. Data will also be obtained on genital tract penetration and placenta transfer of raltegravir to the newborn.