The frequency of HIV-positive women giving birth has "risen significantly" since the beginning of the decade.
But because more than 70 per cent of mothers who are HIV positive do not know that they are infected, their unborn babies are left at greater risk of catching the virus. Positive women who take the test at this time can drastically cut the risk of HIV passing to their babies from one in six to one in 100.
Now midwives will assist in a government campaign launched yesterday to encourage more mothers-to-be to take the test. The number of births to HIV-infected women is now 1 in 500 in London generally and 1 in 6,000 in the rest of the country, says the Department of Health. For inner London the figure is now one in 369.
Yet most women do not realise they have the virus until their baby becomes ill. Only 4.5 per cent had the test during pregnancy and 35 per cent after their child was born and appeared ill. More than 50 per cent only had the test when their child developed Aids.
If a mother knows she is HIV positive when she is pregnant she can be given drug treatments, opt for a Caesarean and refrain from breastfeeding - all of which reduce the chance of the infection being passed on.
Last year, 250 babies were born to HIV infected mothers. This is estimated to have led to about 40 infections in babies in London alone.
The high levels of HIV infections in pregnant women in the capital reflects the substantial population of men and women from Africa. Available data suggests that around 80 per cent of HIV infections are in women born in sub-Saharan Africa.
"Having the courage to opt for an HIV test is an important first step in preventing babies being born with HIV," said the health minister, Tessa Jowell.Reuse content