Association of low birth weight and placental malarial infection in Nigeria.

BACKGROUND Malaria causes significant morbidity and mortality among pregnant women in Nigeria. However, the contribution of malaria infection to neonatal development is incompletely understood. Here we determined the prevalence of placental malarial infection in six communities in Anambra State, Nigeria, between 2005 and 2006, and compare these data to neonatal birth weight. METHODOLOGY Blood samples were obtained from the placenta of 500 parturient mothers and examined for the presence of malaria parasites. Newborn birth weight was then compared with the malaria status of their mothers. RESULTS Placental malarial infection was found in 322 of 500 mothers (64.4%). The prevalence of infection did not differ among the six different Nigerian communities (P = 0.978). Furthermore, there was no difference in infection rates between rural and urban areas (64.9% vs. 64.0%, respectively, P = 0.827). Interestingly, neonates born from mothers with placental malaria had lower birth weights than neonates born from uninfected mothers [2500 g (range 1900 g - 3200 g) vs. 3800 g (range 3200 g - 4700 g), P < 0.001]. Forty-five percent (145/322) of the newborns born from infected mothers were of low birth weight (defined as birth weight less than 2,500 g). CONCLUSION Malaria infection during pregnancy is common in Nigeria and is likely associated with low newborn birth weight.