Page 53 - AIDSBK23C

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the first trimester. The goal in pregnancy should be to bring the viral load to levels that are
undetectable.[291]
All pregnant women should receive antiretroviral therapy. In the vast majority of
circumstances, that therapy should be a highly active regimen that includes zidovudine.
Stavudine and didanosine in combination should not be used unless other regimens are not
available. ART is recommended for women during pregnancy who require ongoing treatment.
ART is also effective in reducing mother-to-child transmission in women with higher CD4
counts. The addition of a maternal and infant nevirapine dose to antenatal zidovudine can reduce
the rate of transmission to below 5%, which is about half the transmission rate achieved by just a
single dose of nevirapine. HIV resistance develops after nevirapine use in up to 60% of mothers
and 50% of infants following a single dose, but the addition of zidovudine and lamivudine for 4–
7 days postpartum can reduce the risk of HIV resistance to 10%.[291]
The U.S. Public Health Service have promulgated guidelines for prevention of mother-to-
child transmission of HIV:[292]

• Combined antepartum, intrapartum, and infant ARV prophylaxis are recommended for
maximal PMTCT
• Combination antepartum ARV regimens containing at least 3 drugs are recommended
rather than single-drug regimens
• Combined ARV prophylaxis is recommended for all pregnant women infected with HIV
regardless of plasma HIV RNA copy number or CD4 cell count
• Initiating ARV prophylaxis after the first trimester, but ideally no later than 28 weeks, is
recommended for pregnant women infected with who do not require ARV for their own
health
• Intrapartum prophylaxis and infant ARV prophylaxis are recommended for women who
do not receive antepartum ARV to reduce risk of perinatal transmission
• The addition of single-dose intrapartum/newborn nevirapine (NVP) to standard
antepartum combination therapy is not recommended because of the potential risk for
development of NVP resistance and lack of added efficacy based on trial results
• A 6-week ZDV chemoprophylaxis regimen is recommended for all neonates exposed to
HIV and should be started as close to time of birth as possible, preferably within 6 to 12 h
of delivery
• Early diagnosis of HIV infection in infants remains a priority
• Decisions regarding use of additional ARV drugs in infants exposed to HIV depends on
multiple factors and should be resolved with input from a pediatric HIV specialist
• In the United States, breastfeeding should be completely avoided given the increased risk
of HIV transmission to the infant and availability of safe formula replacement feeding.

Even abbreviated regimens of zidovudine therapy have been demonstrated to reduce the
rate of perinatal transmission of HIV.[293] A reduction in likelihood of perinatal transmission
<2% is achieved with prenatal, intrapartum, and neonatal use of antiretroviral prophylaxis in
combination with elective cesarean section and avoidance of breast feeding.[181] The rate is
<1% in women with non detectable plasma HIV-1 RNA.[172]