Maternal transmission of human immunodeficiency virus-1.

The dramatic increase in the number of women of childbearing age infected with human immunodeficiency virus (HIV) has led to the revelation of another terrible consequence of the human immunodeficiency virus (HIV) pandemic; maternal transmission of HIV to the fetus. Over 90 per cent of the children who are infected with HIV contract the virus from their mother. Viral transmission may occur in utero, during labor when the newborn is exposed to maternal blood and body fluids or postnatally, mainly via breast-feeding. However, the risk of infection for a baby whose mother is an HIV carrier is not yet clear. The determination of the HIV status of the newborn remains a major diagnostic problem as the routine test, which detects antibodies to HIV, is of limited value in evaluating newborns. A summary of all of the large prospective long-term follow-up studies reported to date, shows an overall transmission rate of 22.4 per cent, with a 95 per cent confidence interval of 20.5 to 24.0 per cent. However, it is difficult to refer to the wide range of reported transmission rates, from 9.1 to 55.0 per cent, as they are confounded by the differing distribution of risk factors. The risk of maternal to newborn transmission must, therefore, be determined according to the specific characteristics of each parturient population.