The number of women becoming infected with HIV is fast catching up with the number of men, research has found.
AZT: approved for use during pregnancy
Healthcare analyst Isis Research found that this was mainly due to the fact that 51% of newly diagnosed HIV patients contracted the virus through heterosexual contact, compared with just 36% through homosexual contact.
Ten years ago, the split was 28% heterosexual against 38% homosexual.
The rest of cases contracted HIV through non-sexual contact.
Experts are warning that this shift towards heterosexual infection carries with it the risk that increasing numbers of babies will be born to HIV positive mothers.
And it raises questions about which HIV treatments can be safely used during pregnancy.
There is growing concern that HIV is becoming increasingly resistant to current drug treatments.
But at present, AZT is the only drug fully approved for use during pregnancy.
The researchers focused on 3,000 patients across Europe who were being treated for HIV infection between July and October 2002.
Researcher Amanda Zeffman said the figures suggested a worrying level of complacency about HIV among the heterosexual community.
She said: "Governments must now turn their attention to the rise in transmission via heterosexual contact.
"It appears that despite all the evidence, many European heterosexuals are continuing to live in denial of the fact that they could be at risk from HIV and complacent that they are safe.
"Whilst a return to the shock awareness campaigns of the early 90s may not be welcomed, it is clear that there is a great need for a new awareness campaign if the spread of infection via this route is to be minimised in the coming years."
In the US, infections via homosexual contact still account for 51% of new cases, compared with 31% via heterosexual contact.
On a positive note, needle-exchanging initiatives across Europe seem to have been effective with transmission via intravenous drug use (IVDU) now almost eradicated in most European countries.