If a woman gets infected with the human immunodeficiency
virus (HIV) and becomes pregnant, then the primary
medical goal is to prevent the baby from becoming
infected. Recent studies have helped clarify whether
a planned Cesarean section can prevent what is called
vertical transmission. In other words, some exposure
of the baby to HIV virus does not occur until mother
undergoes labor and delivery. At that time the virus
must cross over from mother's blood to baby's blood.
The question has been asked for quite a while as to
whether C-section could prevent any instances of transmission.
Before treatment with the antiviral drug zidovudine
(ZDV), it did not seem that C-section had much effect.
However ZDV has been shown to reduce the transmission
rate itself and most women are now on ZDV therapy
during pregnancy.
A recent publication from the American College of
Obstetricians and Gynecologists, Scheduled Cesarean
delivery and the prevention of vertical transmission
of HIV infection. ACOG Committee Opinion. 1999;219:1-3,
has given us information about HIV and pregnancy.
How likely is the baby to get infected with
HIV?
Without any ZDV treatment or C-section, about 25%
of babies become infected with the HIV virus. When
ZDV therapy is given to a woman during pregnancy,
the incidence of infection is reduced to about 5-8%.
When C-section is performed and ZDV is given during
labor, the infection rate is further reduced to about
2%. It is on this basis that current recommendations
are to perform scheduled C-Section after 39 weeks
in order to minimize the chance of newborn infection.
Won't a Cesarean section result in many more
complications for a woman with HIV than a vaginal
delivery?
Women who have low CD4 cell counts seem to have the
most postpartum complications. This makes sense because
those women have the most active disease with probably
the greatest viral loads. Women with very low viral
load counts of less than 1000 viral copies per ml
of plasma (presumably due to effective ZDV therapy)
actually have very low rates of the baby being infected.
In these cases, C-section does not actually improve
the newborn infection rate.
What if a woman with HIV doesn't want to
have a C-section?
Women always have autonomy in whether or not to have
surgery regardless of the effect on the baby. Courts
have long upheld that a woman can refuse surgery even
though that refusal may result in the baby dying or
being significantly harmed directly due to that refusal.Informed
consent for this scheduled delivery is necessary and
whatever a woman decides should be honored.
What kind of drug treatment should be given
around the time of delivery?
Women with HIV should receive during pregnancy whatever
antiviral chemotherapy is recommended according to
current adult guidelines. Then in addition, they should
receive intravenous therapy with an antiviral like
ZDV starting about 3 hours before and then during
the Cesarean delivery. The baby will then receive
oral ZDV syrup for the first 6 weeks of life. Right
now this is the best therapy for minimizing HIV infection
in the newborn.
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