Knowledge about the factors or situations that influence the vertical transmission (VT) of human immunodeficiency type 1 (HIV-1) has led to the implementation of strategies which have promoted a rate decline along the years, from 40% to less than 3% nowadays. One of the major advances in the area has been the prophylactic administration of zidovudine (AZT), in the prenatal phase (oral route), in the predelivery phase (intravenous route) and to the newborn (oral route). This intervention may reduce HIV-1 VT 68%, thus being the most effective isolated strategy used so far. In the chronological sequence of advances, it has been observed that a high viral load is the main risk indicator for this type of transmission. As AZT does not reduce the viral load and does not control the residual rate observed in HIV-1 VT, the use of prophylactic schemes using three antiretroviral drugs has been encouraged. Elective caesarean section completes the range of obstetric strategies with major impact on the reduction of HIV-1 VT. Its effectiveness is linked to the observation of the criteria for its indication: viral load assessed after the 34th week of pregnancy with levels over 1000 copies/mL, gestation over 38 weeks confirmed by ultrasonography, intact chorioamniotic membranes, and performed before labor has started. In cases where normal delivery is indicated, it should be remembered that prolonged chorioamniorrhexis, invasive manipulation of the fetus, delivery with instruments and episiotomy are situations to be avoided. Among the postnatal interventions considered important for the reduction of HIV-1 VT are: pediatric reception (this should be done by trained professionals, avoiding microtraumas in the mucosa during the sucking maneuvers, use of neonatal AZT (for a period of six weeks) and bottle feeding. Special attention should be given to the orientation for the mother, in order to prevent acute infection by HIV-1 in this period, what would markedly increase virus VT rate.
Disease transmission; HIV-1; Interventions; Anti-HIV agents; Prenatal care; Cesarean section
