In the womb the baby is surrounded by a thin sack. If the mother has HIV this sack acts as a barrier and prevents the virus from passing to the baby. During delivery this sack breaks and the mother's body fluids that may contain HIV are mixed with the baby's fluids, putting the baby at risk of getting HIV. Drugs given to the mother and child during pregnancy and after birth can prevent the baby from becoming infected-ask a health worker about a program called PMTCT (Prevention of Mother to Child Transmission).
Attribution: Straight Talk Foundation