By Martine O’Callaghan
HIV, human immunodeficiency virus, is the retrovirus which causes AIDS, acquired immunodeficiency syndrome. AIDS destroys the immune system a complex set of glands, organs and tissues that help protect against and fight off diseases. HIV is blood borne and it can only be transmitted via bodily fluids such as blood, semen and vaginal mucus. It is, therefore, sexually transmitted but can also be passed on by sharing hypodermic needles or needle stick injuries, tattoo needles, etc.
Perinatal transmission of HIV is passing on the infection from mother to baby during labour and through breast milk. This is one of the reasons that pregnant women are encouraged to be tested to establish their HIV status.
Why test for HIV during pregnancy?
All women except those known to be HIV positive are offered voluntary testing during pregnancy. Women can also be tested during labour using tests which can read in less than an hour. Should the result come back as positive, this will enable health care professionals to put protective measures in place to reduce the risk of the baby becoming infected.
That HIV can be passed on to the baby is not the only reason expectant mothers are advised to be HIV tested. A woman testing positive who was previously unaware of her status may need to begin anti-retroviral treatment and / or immunomodulators – drugs that alter the way in which the immune system works. She may be encouraged to review her vaccination status during pregnancy and catch up on those which would be safe for someone with a compromised immune system, that is one that is functioning below par, to receive.
It is also important that the professionals or anyone else near you during the time when you give birth are aware of your status so that any extra precautions can be taken in the event of, say, needle stick injury or loss of blood. Women who are already aware that they are HIV positive should speak to their doctors and midwife if planning to become pregnant or as early in pregnancy as possible.
What happens if the test is positive?
First and foremost, the results of your HIV test and even that you have consented to be tested remains confidential though the result of the test will be recorded in your medical notes. Being diagnosed as HIV positive can come as a huge shock and perhaps even more so when pregnant. This diagnosis, of course, has implications for the rest of the pregnancy and any future pregnancies. It may also have implications for current, previous and future relationships and you will be offered counselling and guided through the steps you may need or want to take should your test result be positive.
If I am HIV positive will I pass it on to my baby?
March of Dimes is a charity that began in the USA in response to the Polio epidemic in the 1950s. Their fund raising and activism was key in the development of the polio vaccines that are still given today. These days, the aim of this organisation is to, “help moms have full-term pregnancies and research the problems that threaten the health of babies.”
They estimate that between one hundred and twenty thousand and one hundred and sixty thousand women in the United States have been infected with the HIV virus. Of those, approximately six to seven thousand become pregnant each year. Without adequate precautions perinatal transmission of HIV can occur.
Data collected by March of Dimes indicates that with the right medication and precautions, the risk of perinatal HIV transmission can be as low as just two per cent – a favourable comparison to the twenty five percent incidence of transmission to babies from women who receive no intervention (some of whom were undiagnosed HIV carriers).
There are many factors affecting the likelihood of passing HIV to your baby. Primary among them is the clinical state of your HIV infection also known as the viral load. This indicates just how much virus is in the blood. Of course, engaging in risky behaviour such as intravenous drug use and unprotected sex may expose you to the virus again and change the viral load. Keeping as healthy as possible and following common sense health guidelines will also help to minimise the chances of transmission.
The placenta, the sac which contains amniotic fluid and the foetus provides a barrier against HIV infection. However, drug use, urinary infections and sexually transmitted infections can compromise this barrier. Malnutrition can also have the same effect and sudden and unexpected weight loss should be reported to your physician immediately. Your care team should provide you with information on how to maintain iron, vitamin and mineral levels during your pregnancy. It may become necessary to take supplements or receive vitamin or iron injections.
Zidovudine. Also known as AZT, ZDV and Retrivir is an anti-retroviral drug prescribed to many people who are HIV positive. It may be prescribed to HIV positive pregnant women in combination with other drugs to lower the risk of perinatal transmission.
Precautions during delivery
There are also precautions to be taken during delivery. Inducing pregnancy by rupturing the placenta – amniotomy – is not advised in women who are HIV positive. Certain other procedures that may risk the baby coming into contact with its mothers bodily fluids are also to be avoided wherever possible. Caesarian section deliveries have been shown to reduce the risk of perinatal HIV transmission.
Will my baby need treatment when he or she is born?
After birth, it is recommended that babies born to mothers who are HIV positive be treated with AZT for the first six weeks of life. Studies have shown that that, even if potentially infected during birth, that the risk of the baby testing positive for HIV after six weeks is reduced by sixty six percent.
Should HIV positive mothers breast feed their infants?
Balancing the benefits of breast feeding infants against the risk of transmitting HIV it becomes clear that the risks far exceed the benefits. A quarter of babies breast fed by mothers who are HIV positive will become infected. The risk is higher from mothers infected after birth but even when comparing women on treatment to those receiving none the rate of transmission hardly fluctuates.
Common problems that affect breast feeding mothers such as mastitis (infection that causes inflammation of the breast tissue) and thrush can greatly increase the risk of transmission of HIV to a nursing baby.
It should be noted, however, that the understanding of how the HIV retrovirus behaves in the body is becoming much better understood. Drug therapies have been developed that mean, for most otherwise healthy people who acquire this infection, it is no longer a death sentence but a chronic but manageable condition. Becoming HIV positive may not mean that this pregnancy need necessarily be the last.