Placental membrane inflammation and risks of maternal-to-child transmission of HIV-1 in Uganda.

This prospective study was conducted to examine the association between placental membrane inflammation and risks of maternal-to-child (vertical) transmission of HIV-1 in Uganda. The cohort study consisted of 172 HIV-infected pregnant women over 15 years old who presented for antenatal care and intended to deliver at Mulago Hospital and their infants. Data on maternal immune status (CD4 counts or clinical AIDS) and concurrent infections with sexually transmitted diseases were obtained. Infants were followed-up for possible HIV infection using polymerase chain reaction for those below 15 months and enzyme immunoassay/Western blot for infants older than 15 months. Placental membrane inflammation and placental villous inflammation were determined by histopathology. Women without any placental pathology were used as reference group to assess vertical transmission rates. Among the 172 mother-infant pairs 40 infants showed evidence of HIV infection giving an overall transmission rate of 23.3%. Women without any placental pathology or immune suppression had an 11.3% transmission rate compared with 25.5% in women with placental inflammation and nonimmunocompromised. Women with immunosuppression had a 37.0% transmission rate. Inflammation of placental villous and artificial membrane rupture did not improve transmission rates and delivery through cesarean section and was associated with nonsignificant risk reduction. Overall the study indicates that placental membrane inflammation increases the risk of vertical transmission of HIV.