Estimates of the rate of human immunodeficiency virus vertical transmission range from 15% to 40%, and the rate is lower in European and American studies than in African studies. There appears to be a relationship between maternal factors, mode of delivery and mother-to-child transmission. The risk factors or markers associated with increased vertical transmission are analyzed in this review. The use of zidovudine, administered to HIV-infected women during pregnancy and labour, and to the offspring for 6 weeks reduce the mother-to-infant transmission rate from 25% to 8%. Other strategies to alter transmission of HIV, including the use of combinaison of anti-retroviral drugs, immunoprophylaxis against HIV or obstetric interventions needs to be evaluated.