Without treatment, one-fourth of them transmit the virus to their children. Treatment with AZT is now the standard of care in this country for preventing HIV infection in infants, although scientists believe that factors other than the virus itself also contribute to infants risk of infection. In the current study, researchers assessed the role that various childbirth conditions and maternal factors play in HIV transmission. HIV infection occurred in 25 percent of babies born to women whose fetal membranes ruptured more than four hours before delivery. In contrast, HIV was transmitted to only 14 percent of babies whose mothers gave birth less than four hours after membrane rupture occurred.
Researchers say the findings have clear implications for the care of pregnant women.
This observation could lead to precautions as simple as not intentionally rupturing the fetal membranes in order to induce or accelerate labor. But this does not mean using interventions that could increase morbidity. Birth canals were cleansed with a mild soap solution containing chlorhexidine, a compound that has been shown to neutralize HIV in laboratory experiments. In general, birth canal washing did not reduce perinatal HIV transmission. But the intervention did appear to make a difference in women who delivered more than four hours after fetal membranes ruptured.