Women who are HIV positive and pregnant, can pass on HIV to their baby when they are pregnant or during labour or delivery. They can also pass on HIV to their baby when breastfeeding. This is known as Mother to Child Transmission (MTCT) or vertical transmission.
How can MTCT be prevented?
There are a number of ways in which MTCT can be prevented (PMTCT). In all instances expert medical advice should be taken, as the information here is only general information provided to help people understand some of the issues involved.1https://aidsinfo.nih.gov/understanding-hiv-aids/fact-sheets/20/50/preventing-mother-to-child-transmission-of-hiv 2Patient education: HIV and pregnancy (Beyond the Basics), 2018, https://www.uptodate.com/contents/hiv-and-pregnancy-beyond-the-basics
It is now recommended that all HIV positive women take HIV treatment as soon as they are diagnosed. If they are not already on treatment then they should be offered an HIV test at their first antenatal visit. If positive they can then start taking HIV treatment at this stage of their pregnancy. Antiretroviral treatment being taken by the mother will help to prevent the baby from getting HIV in the womb.
MTCT - safe labor & delivery
The exact procedure adopted for a safe labor will depend on the country and the resources available. It will also depend on whether the woman has an undetectable viral load as determined by a viral load HIV test. If the woman has a high viral load, then if the resources are available she may during labour be given the HIV drug zidovudine intravenously.3S. Corkery, Pregnancy and birth, 2014, http://www.aidsmap.com/about-hiv/pregnancy-and-birth
The best delivery method to prevent MTCT will also depend on the woman's viral load. If an HIV positive pregnant woman has an undetectable viral load when evaluated within four to six weeks of delivery, then she may choose to have a vaginal delivery even if a cesarean delivery is a possibility. This is because in these circumstances the risk of transmiting HIV to the infant during a vaginal delivery is very low. It is not clear that a cesarean delivery will decrease the risk any further.
But if the woman has a detectable viral load at 34 to 36 weeks of pregnancy she will usually be advised to have a cesarean delivery before she goes into labor if this is a possibility.
Care of the baby, antiretroviral drugs
It is possible that HIV may enter a baby's body during childbirth. Because of this possibility babies born to HIV positive women should receive HIV medicines for 4 to 6 weeks after birth.
Care of the baby, breastfeeding
If a woman has an undetectable viral load this substantially reduces but does not eliminate the risk of transmitting HIV through breast feeding. In well resourced countries where formula milk and clean water is available, women are strongly advised not to breast feed. In other countries women will be advised to exclusively breast feed.
Exclusive breastfeeding means that the infant receives only breast milk. No other liquids or solids are given, not even water. The exception to this is that the baby can be given oral rehydration solution, or drops/syrups of vitamins, minerals or medicines.4World Health Organisation, Exclusive breastfeeding for optimal growth, development and health of infants, https://www.who.int/elena/titles/exclusive_breastfeeding/en/