Maternal malaria during pregnancy and infant mortality rate: critical literature review and a new analytical approach

• Main Author: Ali A. Haghdoost ; Neal Alexander ; Tom Smith
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2007-06-01
• Series: Journal of Vector Borne Diseases
• Subjects: Garki project; infant mortality; maternal malaria
• Online Access: http://www.mrcindia.org/journal/issues/442098.pdf

Background & objectives: Malaria during pregnancy is a recognised risk factor for low birth weightand probably decreases the survival of offspring, particularly during their first month of life. On theother hand, acquired maternal immunity may protect infants against malaria infection or disease.This study assesses these two opposite effects simultaneously.Methods: We used the data of a large epidemiological study on malaria (Garki project) to analyse theimpact of malaria during pregnancy on survival of offspring in their first year of life. The datasetcontains 138,197 survey records, representing 12,849 subjects. Of 663 reported deliveries, 417 couldbe linked to survival data for the newborn.Results: The mortality rate during the first year of life was independent of maternal malaria infectionduring pregnancy (crude rate ratio 1.0). After adjustment for malaria in infancy, the rate ratio was1.2. The corresponding rate ratios for maternal malaria during the second half of pregnancy were1.46 and 1.73. None of these rate ratios was statistically significant. This may be due to the smallnumber of deaths in the first year of life with a complete record of maternal malaria (27 deaths). Theinfants during the first four months of life had the lowest risk for Plasmodium falciparum, P. malariaeand P. ovale infections which may be partly due to acquired maternal immunity. There was a positiveassociation between malaria during pregnancy and malaria during first year of life which might bedue to similarity in exposure risks within a family, or confounding effects of socioeconomic status.However, this association was weaker in the first four months of life, and in those women whocontracted infection during the second half of pregnancy. This may indicate that acquired immunityis stronger in this group and partially protects babies for a few months.Interpretation & conclusion: It seems that on the whole, malaria during pregnancy was not a majorrisk factor for infant mortality in the Garki project. These results suggest that ignoring acquiredmaternal immunity may overestimate the hazard of malaria during pregnancy on infant survival.