Pathological changes of the placenta in HIV infected mothers in Dar es Salaam, Tanzania.

This is a descriptive cross sectional study of pathological changes of placementas of human immunodeficiency virus (HIV) infected pregnant mothers which was conducted at the Department of Histopathology. The study comprised of a total of 105 placentas from, 70 HIV infected and 35 non –HIV infected, pregnant mothers who delivered at Muhimbili Medical Centre (M.M.C) labour ward and who volunteered to be tested for HIV. Placentas were fixed in a 10% phosphate buffered formalin in a broad based container with a cover, for at least two days and thereafter sectioned, processed, paraffin embedded and routinely stained using standard histological techniques. Special stains such as histochemical techniques were used to confirm doubtful cases while the Avidin Biotin Complex (ABC) immunoperoxidase method was used for cellular immunophenotyping of inflammatory cells in the placentas and for demonstration of endothelial and epithelial cells. Placentas of HIV infected mothers showed increased placental weights (mean 623 gms), higher frequencies of excessive plasma exudate 51 (72.9%), funisitis 37 (52.6%), vascular intimal thickening of the cord 37 (52.6%) and epithelial abnormalities 57 (81.4%) than non HIV infected mothers which was statistically significant (p<0.05). There were also more frequencies of placentitis 49 (70.0%), chprioaamnionitis 68 (97.1%), severe degenerative changes and haemorrhage 19 (27.1%) in the placentas of HIV infected mothers than in the control group. Chronic inflammatory reactions predominated in the HIV positive mothers with preponderance of T cells while malaria and tuberculosis were the only concurrent infections observed. Malaria parasites and inflammatory cells were commonly found in the intervillous space and rarely in the chorionic villi. There were no specific placental lesions associated with HIV infection despite the increased frequencies and severity of some placental lessions in HIV infected mothers. Inflammatory reactions in the placentas, cords, and membranes in this study show far greater frequencies than the data reported elsewhere in other HIV and non HIV placental studies. Further studies to establish reasons for the increased frequency, and ways of preventing or reducing it, is recommended.