Pregnant women infected with HIV/AIDS can transmit the virus to their child during pregnancy, delivery, or while breastfeeding. Without anti-retroviral therapy (ART), the chance that a HIV-positive mother in Africa will pass the virus to her infant is estimated to be 25-35%.1 In Africa, a meta-analysis of seven mother-to-child transmission trials including 3,468 infants found that approximately 50% of those infected with the HIV virus died before the age of two.2
ART reduces, but does not eliminate, the chance that a infant will be infected by its mother, by reducing the concentration of the virus in the blood.3 (More about HIV/AIDS here.)
The Cochrane Review of ART for PMTCT evaluated 18 randomized controlled studies, completed in 16 countries and including over 14,000 participants. These studies used a wide variety of drug regimens which provided different drugs for different durations to mother and/or child. The authors conclude that "Short courses of antiretroviral drugs are effective for reducing mother-to-child transmission of HIV and are not associated with any safety concerns in the short-term."6
Among the regimens recommended in the conclusion is "a single dose of [nevirapine] given to mothers in labour and babies immediately after birth."7
The Disease Control Priorities report estimates that ART reduces MTCT by 33-67%8. A recent review estimates that the specific program mentioned above, "a single dose of NVP given to mothers in labour and babies immediately after birth," reduces transmission by about 40%.9
More on our interpretation of “micro evidence” here.
We have not identified any large-scale success stories in developing countries.
More on our interpretation of “macro evidence” here.
Note: In September 2011, we confirmed a number of errors in the estimates for the cost-effectiveness of deworming published in the Disease Control Priorities report. Based on those findings, we are currently rethinking our use of cost-effectiveness estimates, like the DCP2's, for which the full details of the calculations are not public. For more information, see our blog post on the topic.
The Cochrane Review concludes that there have been no safety concerns identified in the short term, but notes that further research is needed to determine if there are long term effects.15 A later study noted a number of complications in pregnancy possibly associated with ART including pre-term delivery, stillbirth, gestational diabetes, pre-eclampsia, and higher risks of anemia and impaired immune systems for infants.16 We have not found clear information on how common or severe such complications are. The study also notes concerns about drug resistance and suggests further research on the topic.17
The Disease Control Priorities (DCP) report estimates that the when using "a single dose of nevirapine," this program costs $6-$12 per disability-adjusted life year (DALY) averted.18 Using a simple calculation,19 we estimate that $6-$12 per DALY averted is equivalent to $150-$300 per HIV infection averted. (For more on the DALY metric, see our overview of the DALY metric.)
The DCP also cites a number of studies that estimate a considerably higher cost for the use of ART to prevent PMTCT, ranging up to $11,444 per HIV infection averted.20 We would guess that the variation is due to differences in which specific drug regimen is implemented.
Note: In September 2011, we confirmed a number of errors in the estimates for the cost-effectiveness of deworming published in the Disease Control Priorities report. Based on those findings, we are currently rethinking our use of cost-effectiveness estimates, like the DCP2's, for which the full details of the calculations are not public. For more information, see our blog post on the topic.
"Based on a review of 13 cohort studies the risk of vertical transmission of HIV without antiretroviral treatment was estimated to be about 15-20% in Europe, 15-30% in the USA, and 25-35% in Africa." Volmink et al. 2007, Pg 4.
"Principal investigators of all nine clinical trials undertaken in sub-Saharan Africa were asked to participate in this study; seven agreed to a combined analysis of their mortality data in children of HIV-infected mothers ... 3468 singleton children were included in this analysis ... By age 1 year, an estimated 35·2% infected and 4·9% uninfected children will have died; by 2 years of age, 52·5% and 7·6% will have died, respectively." Newell 2004.
"The WHO recommends various initiatives to improve initial testing of pregnant women with, at minimum, a rapid HIV test at approximately 20 weeks gestation. Rapid testing has many advantages compared with laboratory-based ELISA testing, including avoiding the transportation of specimens and return clinic appointments for women to receive results, ensuring that women booking late in pregnancy receive their results prior to delivery, and saving time at busy clinics." Maheswaran and Bland 2009.
"For universal treatment with 30% HIV-1 seroprevalence, the HIVNET 012 regimen would avert 603 cases of HIV-1 in babies, cost US$83,333, and generate 15,862 DALYs...For targeted treatment at 30% seroprevalence, HIVNET 012 would cost $141,922 and avert 476 cases at $298 per case averted or $11.29 per DALY. With seroprevalence higher than 3.0% for universal and 4.5% for targeted treatment, the HIVNET 012 regimen was likely to be as cost effective as other public-health interventions." Marseille et al. 1999, abstract.
Volmink et al. 2007, abstract.
"a single dose of NVP given to mothers in labour and babies immediately after birth seems to be effective and feasible." Volmink 2007, abstract.
"Significant reduction in mother-to-infant HIV transmission in the intervention group was found in all eight studies, with a range of 33 to 67 percent reduction in transmission." Jamison et al. 2006, Pg 338 (Table 18.3).
"Single-dose nevirapine (sdNVP) administered to women at the onset of labor and to infants within 72 h of delivery has been widely used in PMTCT programs throughout Africa owing to its feasibility and low cost, reducing transmission by approximately 40%, from a rate of 20% to 12%, at 6-8 weeks postpartum." Maheswaran and Bland 2009.
Jamison et al. 2006, Pg 43.
"Although the transmission of HIV from mother to child is not of great epidemiological importance, since the infected children are very unlikely to transmit the disease, it is a mode of transmission that can be blocked, and which currently accounts for perhaps half a million deaths a year. Short courses of single anti-retrovirals can halve transmission risk from about 40% to 20%." Jamison, Jha and Bloom 2008, Pg 37.
Copenhagen Consensus 2008.
"Although the transmission of HIV from mother to child is not of great epidemiological importance, since the infected children are very unlikely to transmit the disease, it is a mode of transmission that can be blocked, and which currently accounts for perhaps half a million deaths a year. Short courses of single anti-retrovirals can halve transmission risk from about 40% to 20%." Jamison, Jha and Bloom 2008, Pg 37.
Jamison, Jha and Bloom 2008, Pg 51.
"Short courses of antiretroviral drugs are effective for reducing mother-to-child transmission of HIV and are not associated with any safety concerns in the short-term ... The long term implications of the emergence of resistant mutations following the use of these regimens require further study." Volmink et al. 2007, abstract.
"Pregnancy-related complications include a risk of pre-term delivery associated with combination ARV, stillbirth, hepatotoxicity in pregnant women (particularly those with CD4 counts >250 cells/mm3) taking NVP, gestational diabetes and pre-eclampsia. AZT has been linked to anaemia and neutropenia in infants." Maheswaran and Bland 2009.
“Viral resistance in women and children previously exposed to ARV prophylaxis during PMTCT programs raises concerns regarding future ART in women and children.” Maheswaran and Bland 2009.
"Prevention of mother-to-child transmission using a single dose of nevirapine in generalized epidemic settings (US $6 to $12 per DALY averted) stands out for its combination of well-documented high cost-effectiveness and significant avertable infections and deaths." Jamison et al. 2006, Pg 43.
25 DALYs per infection averted: "The estimates of cost per disability-adjusted life year (DALY) saved assume a uniform 20 DALYs lost per infected adult (Murray and Lopez 1996) and 25 DALYs lost per infected child (Marseille and others 1999) and do not account for the increasing proportion of people living with HIV/AIDS in developing countries who will have access to antiretroviral therapy over the coming years." Jamison et al. 2006, Pg 344.
See Jamison et al. 2006, Pg 341 (Table 18.4).