HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION AND PREGNANCY

Vertical transmission from mother-to-child is the main mode of acquisi tion of HIV infection in children. Infection may be acquired before, d uring, or after birth, but the relative contribution of each of these routes remains unknown. Estimates of the rate of vertical transmission range from 15% to 39%, and the rate is lower in European studies than in African studies. This variation reflects differences in distributi on of risk factors associated with vertical transmission, including ma ternal clinical and immunological HIV status, and breastfeeding. There is some suggestion that mode of delivery may also be associated with the likelihood of transmission. About 25% of infected children develop AIDS in the first year of life; the prognosis for the remainder is le ss clear. Increasingly, attention is being given to approaches that ai m to reduce vertical transmission, such as avoidance of breastfeeding, cleansing of the birth canal, antiretroviral therapy and passive or a ctive immunization.