Mother-to-child transmission (MTCT) is when an HIV-infected woman passes the virus to her baby. This can occur during pregnancy, labour and delivery, or breastfeeding. Without treatment, around 15-30% of babies born to HIV positive women will become infected with HIV during pregnancy and delivery. A further 5-20% will become infected through breastfeeding.1
Is MTCT a major problem?
In 2008, around 430,000 children under 15 became infected with HIV, mainly through mother-to-child transmission. About 90% of these MTCT infections occurred in Africa where AIDS is beginning to reverse decades of steady progress in child survival.2 In high income countries MTCT has been virtually eliminated thanks to effective voluntary testing and counselling, access to antiretroviral therapy, safe delivery practices, and the widespread availability and safe use of breast-milk substitutes. If these interventions were used worldwide, they could save the lives of thousands of children each year.
How can MTCT be prevented (PMTCT)?
[pic]An HIV positive mother and her HIV positive baby in India Effective prevention of mother-to-child transmission (PMTCT) requires a three-fold strategy.3 4 • Preventing HIV infection among prospective parents - making HIV testing and other prevention interventions available in services related to sexual health such as antenatal and postpartum care. • Avoiding unwanted pregnancies among HIV positive women - providing appropriate counseling and support to women living with HIV to enable them to make informed decisions about their reproductive lives. • Preventing the transmission of HIV from HIV positive mothers to their infants during pregnancy, labour, delivery and breastfeeding. • Integration of HIV care, treatment and support for women found to be positive and their families. The last of these can be achieved by the use of antiretroviral drugs, safer infant feeding practices and other interventions.
Treatment for the mother
Women who have reached the advanced stages of HIV disease require a combination of antiretroviral drugs for their own health. This treatment, which must be taken every day for the rest of a woman's life, is also highly effective at preventing mother-to-child transmission (PMTCT). Women who require treatment will usually be advised to take it, beginning either immediately or after the first trimester. Their newborn babies will usually be given a course of treatment for the first few days or weeks of life, to lower the risk even further. Pregnant women who do not yet need treatment for their own HIV infection can take a short course of drugs to help protect their unborn babies. The main options are outlined below, in order of complexity and effectiveness.
Single dose nevirapine
The simplest of all PMTCT drug regimens was tested in the HIVNET 012 trial, which took place in Uganda between 1997 and 1999. This study found that a single dose of nevirapine given to the mother at the onset of labour and to the baby after delivery roughly halved the rate of HIV transmission.5 6 As it is given only once to the mother and baby, single dose nevirapine is relatively cheap and easy to administer. Since 2000, many thousands of babies in resource-poor countries have benefited from this simple intervention, which has been the mainstay of many PMTCT programmes.
When is single dose nevirapine appropriate?
A significant concern about the use of single dose nevirapine is drug resistance. Around a third of women who take single dose nevirapine develop drug resistant HIV,7 which can make subsequent treatment involving nevirapine and efavirenz (a related drug) less effective.8 Studies have found that drug resistance resulting from single dose nevirapine tends to decrease over time; if a mother waits at least six months before beginning treatment then it may be less likely to fail.9 10 Nevertheless, in some cases...