Haematological parameters and immune status of HIV-positive pregnant women at University of Port-Harcourt Teaching Hospital (UPTH). BACKGROUND Pregnancy is associated with changes in the body, physical, physiological and haematological as well as the immune status. Most noted of the haematological changes is anaemia in pregnancy in this environment as a result of multifactorial causes, and also the widely known fact of a depression in the immune status. The study was done to find out the effect of HIV on the haematological parameters and immune status of the HIV-positive pregnant woman. METHOD: One hundred apparently healthy pregnant women who were seropositive for HIV were enrolled .Twenty-five seronegative pregnant women, and 25 seronegative non-pregnant women served as controls. Blood samples were collected from these pregnant and non-pregnant women who had already been screened for HIV and analysed manually for PCV, T-WBC, platelets and differentaials, as well as CD4+ lymphocyte count. RESULT: Anaemia is common in the general population of women, both seropositive and seronegative pregnant and non-pregnant women in this environment. The mean haematocrit was highest in the HIV-seronegative, non-pregnant women,and lowest in the pregnant HIV seropositive women. It fell at the rate of 1% from the highest to the lowest. The mean haematocrit was 31 ± 4.0% in the HIV-negative, non-pregnant women, 30 ± 3.0% in the HIV negative pregnant women and 29 ± 4% in the HIV-positive pregnant women. The mean haematocrit fell in the 2nd trimester in both seropositive and seronegative, and although it rose in the 3rd trimester in the seronegative pregnant ones, it remained the same in the seropositive pregnant women. There was leucocytosis in both pregnant groups. The platelet count was found to be within the normal range, but higher in the seropositive group. The mean CD4+ count was observed to fall in pregnancy in the apparently normal pregnant HIV-negative (480 cells/ul), 1 compared to the non-pregnant group (751 cells/ul), but depreciated more with HIV seropositivity (267 cells/ul). CONCLUSION: This study has shown that the main haematological parameters affected in pregnancy are the haematocrit and the white blood cell count. Although there is anaemia generally in the normal population of women, the incidence was highest in pregnancy and even more with HIV infection, and there is a significant decline in the immune status in pregnancy, and furthermore with HIV superimposed. It is worthy of note that for a good implementation of the Prevention of mother to child transmission (PMTCT) programme, before commencement of Antiretroviral therapy (ART), and for long term prophylaxis, laboratory investigations including the haematological parameters, the CD4+ count must be done and monitored in the pregnant woman,as is routinely done for non-pregnant HIV- positive persons. Keyword: Haematological parameters, immune status, pregnant women, HIV seropositivity, Antiretroviral therapy (ART), Prevention of mother to child transmission (PMTCT).