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ACRIA Update
Winter 2008 - Vol. 17 No. 1
Positive Pregnancy
by Vaughn
Taylor and Hanna Tessema
Many
HIV-positive women are reluctant to become pregnant because they fear
they will pass the virus to their fetuses or that they will become too
sick or disabled to care and provide for their children properly. But
with counseling and guidance, along with comprehensive healthcare and
treatment, many HIV-positive women can have healthy, HIV-negative
children.
The key to a successful pregnancy is the health of the
mother-to-be. The HIV-positive woman who is pregnant – or is
considering having children – has an additional reason to take care of
herself. Living well with HIV isn’t just about antiretrovirals –
it’s also about adequate nutrition, quitting smoking, getting enough
exercise, and not using recreational drugs (especially those that
involve needles). These recommendations will become even more
vital during pregnancy, and will be joined by others – avoiding alcohol
and caffeine, for example. The aim is a healthy pregnancy, an
HIV-negative baby, and a long, healthy life as a caring mother.
The prospective mother needs to learn everything she can about risks to
the fetus during pregnancy and to the baby after delivery. She
needs to discuss her options with both her HIV specialist and her
obstetrician (and later her baby’s pediatrician), in order to determine
the choices that are best for her. This article will explore some
of those options.
The Importance of
Prenatal Care and Counseling
Researchers are not sure exactly when HIV is transmitted during
pregnancy. While some fetuses can be infected with HIV while
developing inside their mothers’ uteruses (wombs), the vast majority of
infections occur during labor (the time of delivery) or after the baby
is born and is breastfed by an HIV-infected mother.
Ideally, preparation for reducing risks to mother and child begins
before conception, when the woman and her partner are deciding if,
when, and how to have a baby. Without treatment, there is a 25%
to 30% chance of an HIV-positive woman passing the virus to her child –
so-called “vertical transmission.” Risk of mother-to-child
transmission is generally dependent on the pregnant woman’s viral load
– the higher the amount of virus during pregnancy and delivery, the
greater the higher the chance of transmitting the virus to her baby.
Throughout pregnancy, a developing fetus has its own blood
supply. In other words, the developing fetus generally does not
come into contact with the blood of the mother. This helps
protect the fetus from infections, such as HIV, in the mother’s blood.
Developing fetuses do, however, receive nutrients and various
proteins, such as immune system antibodies, from their mothers.
While a mother’s HIV may not enter the fetus, her antibodies to the
virus will. These antibodies cannot harm the fetus, but will
cause the baby to test “positive” to an HIV antibody test at birth.
At the time of birth (labor), a baby often comes into contact with his
or her mother’s blood. If the mother’s blood enters the baby’s
body, HIV can be transmitted. But with good prenatal care and
antiretroviral treatment, the risk of transmission can be reduced to
less than 2%.
Sperm Washing
Sperm washing is a process that was developed to reduce risk of
transmission from an HIV-positive man to his HIV-negative partner, and
subsequently to the fetus, while enabling them to conceive a
child. If both partners are positive, sperm washing also reduces
the risk of cross-infection with a different strain of HIV.
HIV is carried primarily in the seminal fluid rather than in the sperm
itself. Sperm washing involves separating the sperm from the
seminal fluid, then using it to impregnate the woman when she is
ovulating and most likely to become pregnant, or to fertilize her egg
through in vitro fertilization.
Integrated Pregnancy
Care
A comprehensive approach to care is the most effective way for a
pregnant woman with HIV infection to have a healthy pregnancy and
delivery. While an obstetrician and an HIV specialist are safely
and effectively managing the woman’s pregnancy, she should also be
provided with professional support to help manage psychological,
social, and economic challenges should they arise. This might
include assistance from a social services agency to help her with
counseling, housing, food, and childcare needs, both during pregnancy
and after delivery.
Professional counseling before pregnancy can also be extremely
helpful. Working closely with her healthcare provider, an
HIV-positive women and her partner can learn a great deal about the
risks and benefits associated with pregnancy, including treatment
options, and different ways of achieving conception.
Antiretroviral
Therapy
Women who are HIV positive can drastically reduce the risk of
transmitting HIV to their babies with the use of antiretroviral drug
treatment during pregnancy and at the time of delivery. Deciding
when to begin antiretroviral therapy during pregnancy, however – if
it’s not already being taken – and which medications to use can be
confusing.
Working with a healthcare provider, HIV-positive women can make
important perinatal treatment decisions that best suit their individual
needs, while at the same time following state-of-the-art
recommendations from the U.S. Department of Health and Human Services
(DHHS), the federal agency responsible for setting healthcare policies
in the United States. The most recent version of the agency’s
guidelines, entitled Recommendations for Use of Antiretroviral
Drugs in Pregnant HIV-1-Infected Women for Maternal Health and
Interventions to Reduce Perinatal HIV-1 Transmission in the United
States, was published on November 2, 2007.
When to Use
Treatment During Pregnancy
Generally speaking, if an HIV-positive woman requires treatment to
protect her own health – if her CD4 cell count is below 350, for
example – she should not be denied therapy, regardless of whether she
is pregnant or plans to become pregnant.
There are lingering questions about the safety of antiretrovirals when
used during the first three months (first trimester) of pregnancy, when
a developing fetus is believed to be most susceptible to drug
toxicity. According to the DHHS, antiretrovirals can be avoided
during this three-month period provided the woman does not require
treatment to maintain her own health. Otherwise, HIV treatment
should be continued throughout pregnancy.
HIV-positive pregnant women who do not require antiretroviral therapy
to maintain their own health may be able to stop treatment after giving
birth – a decision that should only be made in consultation with her
healthcare team.
Which HIV Drugs to
Use During Pregnancy
As for specific HIV medications, the DHHS guidelines spell out a number
of important considerations that HIV-positive pregnant women and their
healthcare providers should be aware of.
First, the nucleoside reverse transcriptase inhibitor (NRTI) Retrovir
(zidovudine) has been studied extensively in HIV-positive pregnant
women and has been shown to be safe and effective at reducing the
transmission of HIV from mother to fetus. In turn, it is almost
always recommended as a treatment component during pregnancy and
delivery (and given to the infant after birth), even when the woman has
HIV that is resistant to it.
The non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz,
found in Sustiva and Atripla, should not be used by pregnant women and
only cautiously by women who might become pregnant. Because
efavirenz may cause birth defects if taken during the first trimester –
the first three months of pregnancy – it is recommended that
HIV-positive women have a pregnancy test before starting efavirenz and
use adequate birth control while using the drug.
The NNRTI Viramune (nevirapine) has been shown to reduce the risk of
mother-to-child HIV transmission, but it is recommended only for women
with CD4 counts below 250 cells. There is a higher risk of serious
allergic reactions, including liver damage, occurring in women who
start Viramune with CD4s higher than 250.
The protease inhibitor Viracept (nelfinavir) should also be avoided
during pregnancy, until further notice. In September 2007, Pfizer
reported the discovery of a manufacturing impurity, ethyl
methanesulfonate (EMS), in U.S. batches of Viracept. As EMS has
been found to be cancerous and capable of causing birth defects in
animals, the U.S. Food and Drug Administration (FDA) recommends
avoiding Viracept during pregnancy until Pfizer has found a way to
remove EMS from the drug.
It is also a good idea to switch off medications known to cause serious
side effects in women during pregnancy. For example, the FDA has
warned that HIV-positive pregnant women should not take Zerit
(stavudine) and Videx (didanosine) at the same time. Some
pregnant women who took these drugs together developed lactic acidosis
– a serious and sometimes fatal buildup of lactic acid in the blood,
which can cause fatigue, nausea/vomiting, painful inflammation of the
pancreas, and liver damage.
Other Considerations
During Pregnancy
It is important to remember that pregnancy-related complications
typically seen in women who are not living with HIV, such as
hypertensive disorders, ectopic pregnancy, gestational diabetes,
psychiatric illness, preterm delivery, and STDs, also can occur in
pregnant women living with HIV.
Finally, there are some aspects of typical prenatal care that might not
be suitable for HIV-positive pregnant women. For example,
amniocentesis, used to test for genetic defects in the baby, is done
with a needle that passes through the mother’s abdomen and into the
womb. While this test may be necessary to look for any genetic
problems that a developing baby may have, it can also increase the risk
of transmitting HIV. Before undergoing amniocentesis,
HIV-positive pregnant women may want to discuss its benefits and risks
with their healthcare provider.
Labor and Delivery
Labor and delivery are believed to be riskiest time for HIV
transmission during pregnancy, as babies are most likely to be exposed
to their mother’s blood during the birthing process. To reduce
this risk, healthcare providers should avoid performing amniotomies –
intentionally rupturing the amniotic sac to “make the water break” and
induce labor. The risk of transmission increases by 2% for every
hour after membranes have been ruptured.
An episiotomy – a surgical incision through the perineum made to
enlarge the vagina and assist childbirth – can also expose the infant
to the mother’s blood and increase the danger of transmission.
What’s more, the use of birthing instruments and common procedures,
such as forceps/vacuum extractors, scalp electrodes, scalp blood
sampling, and internal fetal monitoring, can cause small tears in the
baby’s skin and increase the risk of transmission further.
Cesarean Sections
vs. Vaginal Delivery
A Cesarean section – also referred to as C-section – is delivery via a
surgical incision through the maternal abdomen and uterus. It is
one of the oldest documented surgical procedures. A C-section is
performed when a vaginal birth is not possible or is not safe for the
mother or child. Because of a variety of medical and social
factors, C-sections have become fairly common – about 26% of all births
in the United States in 2002 were C-sections.
C-sections can greatly reduce an HIV-positive woman’s risk of passing
along the virus to her baby at the time of birth, as they greatly
reduce the amount of time a baby remains in contact with his or her
mother’s blood and other fluids during delivery. It is still not
known, however, if C-sections are any more effective than if the woman
takes a powerful combination of antiretroviral drugs throughout her
pregnancy. It is also not known if a woman who takes a powerful
HIV drug combination and has a C-section has a lower chance of passing
along the virus to her baby than a woman who takes HIV drugs and has a
vaginal delivery.
Some experts do not like the idea of C-sections used solely to reduce
the risk of mother-to-child HIV transmission. Because C-sections
are a type of surgery, there are risks of infection and other
complications. In fact, HIV-positive women may be at a higher
risk for infection while undergoing C-section delivery or other
complications than HIV-negative women. It is also important to remember
that combination HIV treatment might do a better job of stopping
transmission than a C-section. According to some studies, in
HIV-positive pregnant women who have an undetectable viral load at the
time of birth, the risk of delivering a baby infected with the virus is
less than 2%, even with vaginal delivery. It is not known if C-sections
reduce this risk further.
In its perinatal treatment guidelines, the DHHS says that C-sections
are only recommended for the purpose of reducing the risk of
mother-to-child HIV transmission when the mother’s viral load is higher
than 1,000 at week 36 of the pregnancy. A woman with a viral load
below 1,000 should be counseled that her risk of transmitting the virus
to her baby is low and that there is currently no information
concluding that performing a scheduled cesarean section will lower her
risk further. DHHS also says that, if C-section delivery is
chosen, it should be scheduled for week 38 of the pregnancy.
Postnatal Treatment
The months following delivery of a baby by an HIV-positive woman are
also crucial to keeping the risk of vertical transmission to a minimum.
After the baby is born, the doctor will likely advise that he or she
take anti-HIV drugs for four to six weeks, usually a liquid form of
Retrovir taken two or four times a day, possibly in combination with
other HIV medications. Studies suggest that the use of
antiretroviral treatment during the first few weeks of life plays a
role in further lowering the risk of HIV infection in a newborn
baby. No significant side effects of Retrovir have been observed,
other than a mild anemia in some infants that cleared up when the drug
was stopped. Follow-up studies show that the HIV-negative treated
babies continued to develop normally.
Learning the Baby’s
HIV Status
An HIV-positive new mother usually wants to know right away whether her
baby is infected. It can take several months to learn
definitively the HIV status of a newborn. Moreover, it is important to
keep in mind what an HIV test is. The standard test looks for
antibodies to HIV; it does not look for the virus itself. Because
a fetus is exposed to the mother’s HIV antibodies, the baby will
automatically test “positive” after birth. These antibodies can remain
in the baby’s body for more than 18 months after birth.
Most hospitals now conduct nucleic acid testing, which looks for the
virus itself, on babies born to HIV-infected women. This test can
be performed within a few days after delivery and looks for HIV itself
in a blood sample collected from the baby. If the test is
negative, it should be repeated within a few months after the birth.
Breastfeeding
Breast milk also carries HIV, and breastfeeding adds considerable risk
of transmission. As with transmission via blood, there’s some
indication that risk increases along with viral load (the amount of HIV
in the mother’s blood). So far, research shows that the risk of
breast milk transmission is highest in the first six months of
life. There’s no threshold, however, or point beyond which it
becomes absolutely safe to breastfeed.
Wherever clean water and formula are available, it is recommended that
HIV-positive women exclusively formula feed their infants.
In recent years, studies have also looked at breast milk
pasteurization, a procedure that allows women to express their breast
milk and treat it themselves so that it becomes safe for their infants
to drink. Right now, these studies have been done in
resource-poor settings; your doctor may have more information about
this strategy.
Vaughn Taylor is
Manager and Hanna Tessema Associate Manager of ACRIA’s Older Adults
Training and Technical Assistance Program.
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