For some time, researches have identified that there may be a possibility that an HIV-infected pregnant woman who delivers by C/S might have a reduced chance of transmitting HIV to her infant. But it has been difficult to separate just mode of delivery from many other factors (mothers viral load, severity of HIV infection, compromise of her immune system, etc., because many of the studies did not control for many of the factors that would help sort it out. If you are a perinatal nurse, you know that c-sections are not all created equal -- sometimes they are elective, before labor and membranes rupture -- sometimes they are done for fetal distress, sometimes fro non-progression of labor, sometimes because of bleeding (placenta previa, abruption) -- sometimes because of fetal position, etc.
There was new research presented at the international AIDS conference this June in Geneva -- that when researchers studied perinatal transmission -- from mom to baby, that the risk was lowered when AZT (also called ZDV, Zidovudine or Retrovir) was given following the #076 protocol (the mom took AZT prenatally after 14 weeks, it was given to her during labor in an IV infusion, and the baby took it in syrup form for 6 weeks after birth) AND the C/S was done BEFORE labor and when the membranes were still intact. One study reported 0% transmission -- but it was such a small number of patients. Another study reported 3% transmission rate.
Two things to remember: 1) with AZT alone -- following the 076 protocol -- transmission rate has been reported at about 6-7%. 2) The potential morbidity and mortality to a women who has HIV/AIDS of an operative delivery has to be considered -- there have been many reported cases of post-op complications and several maternal deaths. In addition, with the new antiretroviral therapies, many women have had their viral loads reduced dramatically, which is a factor many feel leads to decreased perinatal transmission.