A large-scale analysis showed that depot medroxyprogesterone acetate (DMPA), commonly known as Depo-Provera, was linked to a 40% increase in acquiring HIV infection compared to other forms of contraception, or no contraception. Oral contraceptives did not affect the risk of becoming infected with HIV.
But despite the higher risks, the contraceptive injection remains a good option for many women, Dr Richard Ma, a GP with an interest in sexual health and HIV, told GP.
‘This study needs to be interpreted carefully – it only shows a moderate increase in the risk of acquiring HIV, which is not enough to warrant its withdrawal,’ he said.
Around 8-9% of women using contraception in the UK opt for the injection, according to an NHS Contraceptive Services report.
‘GPs should always talk about STI risk when discussing contraception, particularly with people at high risk. Looking at this study alone, the contraceptive injection shouldn’t be excluded from these discussions,’ Dr Ma said.
In recent decades, the injection’s link to HIV risk has been hotly debated, but attempts to begin a randomised controlled trial have stalled due to funding issues.
Reasons for the increase in HIV susceptibility are as yet unknown, but biological and behavioural mechanisms have been proposed, such as structural changes to the genital tract. Reduced use of barrier methods could also factor in, although this study adjusted for condom use.
‘Whether the risks of HIV observed in our study would merit complete withdrawal of DMPA needs to be balanced against the known benefits of a highly effective contraceptive,’ the study authors, from the University of California at Berkeley, wrote in The Lancet Infectious Diseases.