suggesting that neither pregnancy nor breast-feeding adversely affects achievable rates of virologic suppression. Although concern has been expressed regarding the lower levels of lopinavir in the third trimester of pregnancy,9,10 these levels have not been associated with virologic failure.11 Therefore, although this explanation for the lower percentage of women in the protease-inhibitor group with suppression to less than 50 copies per milliliter at delivery is possible, we believe it is unlikely, particularly among women who had not previously received protease inhibitors