Transmission probabilities according to zidovudine duration, viral load at baseline/delivery, and nevirapine intake.

<p>A. Probability of <i>in-utero</i> HIV transmission as a function of zidovudine duration; B. Probability of <i>in-utero</i> HIV transmission as a function of viral load at baseline. The lines denote the median, 5^th and 95^thpercentiles of the model predictions. The open circles stand for the observed mean proportion of transmission, the solid vertical segments denote the corresponding 95% confidence intervals (numbers at top of each segment stand for the number of women in each time interval or VL interval). C. Probability of <i>intra-partum</i> HIV mother-to-child transmission as a function of viral load at delivery without single dose nevirapine; D. Probability of <i>intra-partum</i> HIV mother-to-child transmission as a function of viral load at delivery with single dose nevirapine.