Anonymous screening of new-born babies in south-east England has shown that of 287 babies born to HIV-positive mothers, only 50 (17 per cent) of the cases were identified before delivery.
More than 40 per cent of obstetrics units in Britain do not have a formal policy on testing pregnant women for HIV, despite evidence that the number giving birth in this category is rising. Most of the women became infected abroad.
Many of the undiagnosed infected women go on to breast-feed their babies, unaware that this is a major route of transmission of HIV, it was revealed in the report from the Institute of Child Health in London. Women whose HIV status is known before delivery are six times less likely to breast-feed than women who were found to be infected only after delivery.
The chances of early diagnosis and treatment for HIV-infected children are also reduced if maternal infection is undiagnosed, according to the report, which is published in tomorrow's British Medical Journal.
The researchers called for more extensive antenatal testing so that infected women could be counselled against breast-feeding. They said this would 'prevent a substantial proportion of vertical transmission (mother to child) in some areas, and would increase opportunities for early diagnosis and treatment.'