Insights on Vertical Transmission

Communities in Crisis Women HIV-positive pregnant women who develop small tears in their placenta during labor are likely to pass the virus along to their newborns, scientists reported in the journal PLoS Medicine. The tears can develop during contractions, allowing HIV-infected blood to enter the umbilical cord and put the infant at risk for infection while still in the womb. Most researchers have believed the vast majority of babies infected with HIV during childbirth contracted the virus in the mother's birth canal.