Drug levels will be summarized with the mean of the 3 values for Cmin and Cmax for each woman for their PI or NNRTI and compared to the mean values of the general HIV population. Cmin and Cmax will be classified into high and low levels with a high level defined as less than or equal to 1.5 X arithmetic population mean for each drug. Characteristics of patients with high drug levels will be compared to those of patients with low drug levels. Univariate and multivariate logistic regression models will be used to identify independent associations of patient characteristics with high drug levels. The proportions of patients with AEs and the median number of AEs per patient will be compared between patients with high Cmax and patients with low Cmax.