Mother to Child

A baby born to an HIV+ mother can be infected either during pregnancy, at birth or via breastfeeding.

Infection during pregnancy

Infection during pregnancy can occur when the mother’s blood reaches the baby after crossing the placenta. The chance of a baby being infected during pregnancy is increased if the mother’s own infection is advanced, if she has used illicit drugs during the pregnancy, if she has had frequent unprotected sex or if the baby is very small or delivered prematurely.  When antiretroviral treatment is given during pregnancy, the risk of transmission is greatly reduced.

Infection during childbirth

There is a risk of infection during vaginal childbirth when the baby is exposed to its mother’s blood and cervical secretions. Premature babies delivered vaginally are particularly vulnerable to infection. The risk of infection is also known to increase when more than four hours elapse between a woman’s waters breaking and delivery of the baby.

Where the option is available, many HIV+ women opt for an elective caesarean birth, as this is known to greatly reduce the risk of transmission. In some instances a woman will be given a single dose of an antiretroviral drug when labour commences, if she is expected to have a normal vaginal birth.

Infection via breastfeeding

Breastfeeding can pose a risk of infection to an infant, as HIV is usually present in breast milk and the colostrum that is produced during the first few days after birth. A baby can also be exposed to its mother’s blood if she suffers with cracked or bleeding nipples. Ideally all women would be advised to avoid this risk of transmission by exclusively bottle-feeding their babies. However, as clean water and sterile bottles are not reliably available in many parts of the world, the risk of HIV infection associated with breastfeeding is far outweighed by the baby’s certain consumption of unclean water used to mix infant formula.

Prevention

Modern drugs are highly effective at preventing HIV transmission during pregnancy, labour and delivery. When combined with other interventions, including formula feeding, a complete course of treatment can cut the risk of transmission to below 2%.

 

Last updated April 2010

Mother to Child