Establishing a conceptual framework of the impact of placental malaria on infant neurodevelopment

Abstract

A novel conceptual framework to describe the relationship between placental malaria and adverse infant neurodevelopmental outcomes is proposed. This conceptual framework includes three distinct stages: (1) maternal and environmental risk factors for the development of placental malaria; (2) placental pathology and inflammation associated with placental malaria infection; and (3) postnatal impacts of placental malaria. The direct, indirect, and bidirectional effects of these risk factors on infant neurodevelopment across the three stages were critically examined. These factors ultimately culminate in an infant phenotype that not only leads to adverse birth outcomes, but also to increased risks of neurological, cognitive, and behavioural deficits that may impact the quality of life in this high-risk population. Multiple risk factors were identified in this conceptual framework; nonetheless, based on current evidence, a key knowledge gap is the uncertainty regarding which are the most important and how exactly they interact.

Keywords: Malaria; Malaria in pregnancy; Neurodevelopment; Placental malaria.

Figure 1:. Conceptual framework to describe the progression from placental malaria to adverse infant neurodevelopment

Risk factors are present at three distinct stages: 1) prior to the development of placental malaria; 2) during placental malaria infection; and 3) postnatally. These risk factors act directly, indirectly, and bidirectionally to culminate in an infant phenotype where we see evidence of neurological, cognitive, and behavioural deficits that impact this high-risk population from infancy, through childhood, adolescence, and into adulthood.