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Prevention of Mother-to-child Transmission of HIV
Table 2: Possible Interventions to Prevent Breast Milk Transmission of HIV
Risk Factor for Transmission Related Intervention
Duration of exposure to breast milk of an HIV-1-infected woman Complete avoidance of breastfeeding*
Higher maternal viral load Maternal antiretrovirals (while breastfeeding) to decrease viral load
Chemical or heat treatment of breast milk to decrease viral load
Factors facilitating transfer of HIV-1 from the breastfeeding mother to the child Prevention and treatment of maternal breast abnormalities and infant candidiasis
Exclusive breastfeeding (avoidance of mixed breastfeeding)*
Child’s susceptibility to HIV infection while breastfeeding Active immunisation
Passive immunisation
Antiretroviral prophylaxis to the infant while breastfeeding*
*Efficacy demonstrated.
Malawi, all infants received one dose of nevirapine at birth with one The USPHS guidelines
28
recommend resistance testing for all pregnant
week of zidovudine, and then were randomised to no subsequent women not currently using ARVs (before starting treatment or
prophylaxis, nevirapine until the age of 14 weeks or nevirapine with prophylaxis) and for all pregnant women receiving ARV therapy who have
zidovudine until the age of 14 weeks. Among infants uninfected at persistently detectable plasma viral loads or sub-optimal viral suppression.
birth, both of the extended prophylaxis regimens conveyed a
significantly lower risk of HIV infection (and a greater likelihood of In settings where adequate staffing and infrastructure exist for utilisation of
HIV-free survival) among infants at nine months of age compared with Caesarean section before labour and before ruptured membranes as an
the control arm.
22
intervention to prevent MTCT of HIV, various issues have been raised. First,
its effectiveness among women with low viral loads or women who are
Future Challenges receiving combination ARV regimens has been questioned. However,
Despite major successes in the prevention of MTCT of HIV, such published data indicate that Caesarean section before labour and before
transmission continues to occur, and there remain a number of significant ruptured membranes is effective in preventing MTCT even among those
challenges if the goal of complete eradication of MTCT is to be realised. pregnant women who have viral loads of less than 1,000 copies/ml
45–49
or
First, primary prevention is essential (i.e. prevention of acquisition of HIV who are receiving combination ARV regimens. Second, cost-effectiveness
infection by adolescent girls and women). Next, increasing the proportion analyses suggest this intervention remains cost-effective even at very low
of women accessing pre-natal care contributes to prevention of MTCT. As rates of MTCT.
50
Third, the potential benefit of Caesarean section before
part of pre-natal care, pregnant women can access HIV diagnostic testing labour and ruptured membranes for prevention of MTCT must be weighed
and, if found to be HIV-infected, can initiate one or more interventions to against possible deleterious effects of surgical delivery for the mother, for
prevent transmission (in addition to accessing appropriate care and the infant and for the obstetrician.
51–54
Caesarean delivery may be associated
treatment for her own HIV infection). The greatest effectiveness of current with an increased risk of post-partum morbidity among HIV-infected
preventative interventions is predicated upon a pregnant woman knowing women compared with uninfected women, but assessment of currently
her HIV infection status before becoming pregnant, or else as early as available data suggest post-partum morbidity rates among HIV-infected
possible during pregnancy. The CDC has recommended ‘opt-out’ HIV women are not sufficiently frequent or severe to outweigh the potential
testing for all individuals aged 13–64 years receiving care in healthcare benefit of Caesarean section for the prevention of MTCT.
28
Analyses of
settings (including pregnant women).
43
HIV testing is treated as part of
routine care, and it is performed unless the patient objects (opts out).
General consent for medical care is considered to encompass consent for
Further research is needed regarding
HIV testing, and no specific consent for HIV testing would be requested or
not only the pathogenesis of and risk
required in order for the testing to be performed. It is specifically
recommended that women who arrive in labour with unknown or
factors for mother-to-child transmission
undocumented HIV infection status be screened with a rapid HIV test, and
of HIV, but also to develop new or to
ARV prophylaxis be initiated based on a positive result on the rapid HIV test
adapt existing interventions for the
(without awaiting confirmation).
43
Re-screening for HIV infection during
pregnancy is emphasised in these guidelines.
43
realities of different settings.
In addition, adverse events and other issues related to utilisation of morbidity of infants of HIV-infected women associated with the mother’s
existing efficacious interventions for prevention of MTCT of HIV must mode of delivery are under way. Although we know the risk must be
be considered. Potential safety problems related to ARVs for extremely small, there are essentially no data regarding the relative risk of
prevention of MTCT include
44
foetal toxicity (e.g. congenital accidental acquisition of HIV infection by obstetricians or other healthcare
anomalies, low birth weight, pre-term birth); short-term adverse workers according to mode of delivery.
54
effects on the mother and/or on the infant (e.g. anaemia or other
laboratory abnormalities); and long-term adverse consequences for Finally, further research is needed regarding not only the pathogenesis of
the child (e.g. cancer). and risk factors for MTCT of HIV, but also to develop new or to adapt
existing interventions for the realities of different settings, especially
Relatively limited information has been published regarding the use of resource-poor settings. In resource-poor settings, where the burden of
ARVs for prevention of MTCT of HIV and the development of resistance. HIV disease is much greater than in resource-rich settings, complete
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