ISPUB.COM The Internet Journal of Parasitic Diseases Volume 3 Number 2 1 of 7 An assessment of the impact of placental Plasmodium falciparum malaria on perinatal outcome in Nigeria C Uneke, F Iyare, I Sunday-Adeoye, J Ajayi Citation C Uneke, F Iyare, I Sunday-Adeoye, J Ajayi. An assessment of the impact of placental Plasmodium falciparum malaria on perinatal outcome in Nigeria. The Internet Journal of Parasitic Diseases. 2007 Volume 3 Number 2. Abstract Apparently healthy women at full pregnancy term were enrolled. At child birth, maternal and placental malaria parasite microscopy, fetal length and head circumference and birth weight were determined using standard techniques. P. falciparum was found in the peripheral blood of 48(16.0%) of the 300 women studied. Women with peripheral malaria infection had significantly higher proportion (54.2%) of placental infection than those without peripheral malaria (3.5%) (χ2=94.4, P<0.05). Of the 278 placental blood samples analyzed, 34(12.2%) had malaria parasites. A significantly higher proportion (33.3%) of malaria infected placentas had the lowest placental weight (0.4kg) (χ2=6.99, P<0.05) and a higher proportion of babies born by mothers with malaria infected placenta had low birth weight (<2.5kg). A higher proportion of infected placenta was associated with lower fetal length and head circumference, although no significant difference was observed (P>0.05). Effective linkages between malaria control and antenatal care programs are advocated to improve perinatal outcome. INTRODUCTION Malaria during pregnancy is a serious problem in sub- Saharan Africa, affecting an estimated 24 million pregnant women [ 1 ]. Each year between 75,000 and 200,000 infant deaths are attributed to malaria infection in pregnancy globally [ 1 , 2 ]. The sub-Saharan Africa records the greatest severity of malaria because about 90% of all deaths attributable to malaria in the world today occur in the sub- region and this is because majority of infections are caused by Plasmodium falciparum, the most dangerous of the four human malaria parasites [ 3 ]. Although P. falciparum infection in pregnancy in sub-Saharan Africa, is usually asymptomatic it largely contributes to maternal deaths and congenital malaria with risk for infant death particularly in areas of lower malaria endemicity [ 1 ]. One of the major features of P. falciparum malaria during pregnancy is the sequestration of the parasite in the placenta which is most common among the primigravidae [ 4 ]. P. falciparum–infected erythrocytes frequently sequester in the intervillous space of the placenta and cause pathologic alterations [ 5 , 6 , 7 ], which is associated with a variety of adverse perinatal outcome including a significant decrease in infant birth weight [ 8 , 9 , 10 ]. Thus placental P. falciparum malaria has been identified as a risk factor for low birth weight (LBW) mainly mediated by intrauterine growth retardation (IUGR) and pre-term deliveries (PTDs), although the exact mechanisms by which malaria leads to LBW remain unclear [ 11 , 12 ]. The distribution of placental P. falciparum malaria in infected gravid women has been described to vary with the endemicity of malaria and acquired immunity [ 12 ]. Histological abnormalities described in parasitized placenta show pathological changes that could reduce the area of syncytium exposed to maternal blood and, thus, impair materno-foetal exchanges [ 5 , 6 ]. Likewise, considerable abnormality in intervillous spaces may jeopardize the nutritional function of the placenta, resulting in poor foetal outcome [ 12 , 13 , 14 ]. Because placental infection may be detected in the absence of peripheral blood parasitemia and may persist after initiation of antimalarial treatment [ 15 ], the diagnosis of placental malaria in pregnancy is therefore very important for both operational and research purposes. Despite the availability of considerable number of literature on malaria in pregnancy in sub-Saharan Africa, the impact of placental malaria on perinatal outcome is poorly documented in many parts of the sub-region including Nigeria. This paucity of scientific data continues to limit the understanding of events at the maternal-fetal interface which encompass immunological and pathological processes which relate to the epidemiological pattern of malaria in pregnancy and on perinatal outcome in areas of both high and low