A BLOODLESS CESAREAN-SECTION AND PERINATAL TRANSMISSION OF THE HUMAN-IMMUNODEFICIENCY-VIRUS

OBJECTIVE: Perinatal transmission of the human immunodeficiency virus is the main pathway for children to become infected with this virus; h owever, the relative contribution and timing of this transmission, whe ther transplacental or by exposure through the birth process, have not yet been elucidated. An obvious question is whether the mode of deliv ery has an impact on this transmission rate. However, a routine cesare an section will primarily diminish the duration of exposure of materna l bodily fluids to the neonate but does not prevent the baby from bein g exposed to maternal blood coming from the uterine incision. The purp ose of this study was to determine whether the rate of perinatal trans mission of human immunodeficiency virus could be significantly lowered by delivering the baby with minimal to no exposure to maternal blood or bodily fluids by the use of a surgical technique termed a ''bloodle ss cesarean section''. STUDY DESIGN: We performed a prospective cohort study in a group of pregnant women infected with human immunodeficien cy virus and evaluated the rate of transmission of this virus to the n eonate on the basis of the mode of delivery. One group of patients was delivered by means of a ''bloodless cesarean section,'' in which the baby was delivered and not exposed to any maternal blood or bodily flu id. The control group gave birth either by vaginal delivery or by rout ine cesarean section. All of the newborns were followed up for a minim um of 15 months or until negative findings were confirmed. Multiple an tenatal, intrapartum, and postdelivery variables were collected and an alyzed. RESULTS: A total of 108 patients were included in this study a nd 14 neonates became infected with human immunodeficiency virus (13%) . Three of 53 infants delivered by a bloodless cesarean section (5.7%) became infected compared with 11 of 55 control patients (20.0%). This was significant at P=.02 and represented an absolute difference in pe rcentage between the 2 groups of 14.3%, which corresponds to a 71.5% r elative reduction in transmission risk (z=2.27, P=.012). Since the use of zidovudine greatly influences the perinatal transmission rate of h uman immunodeficiency virus, the study data were reanalyzed with the e xclusion of patients who used antenatal or intrapartum zidovudine. Two of 32 infants in the bloodless cesarean section group (6.3%) were inf ected compared with 9 of 38 in the control group (23.7%). This was sig nificant at P=.04 and revealed an absolute difference in percentage of 17.4%, which corresponds to a 73.4% relative reduction in transmissio n risk (z=2.15, P=.016). There was no difference in the transmission r ate between the bloodless cesarean section patients who did not use zi dovudine (2/32, 6.3%) and the patients who did use zidovudine from the entire study population (3/38, 7.9%). CONCLUSION: In the absence of z idovudine usage, these data show that 70% to 75% of the perinatal tran smission of human immunodeficiency virus to a newborn occurs from expo sure to maternal blood and bodily fluids at the time of birth. This in formation is important for patients unable to take zidovudine or other antiretroviral agents, but more important, it introduces the concept of other treatment options for the future.