Placental malaria is associated with increased risk of nonmalaria infection during the first 18 months of life in a Beninese population.

BACKGROUND: Several studies have shown that the risk of malaria infection increases for children born to a mother with placental malaria infection. An immune tolerance phenomenon has been hypothesized. We addressed whether Plasmodium falciparum placental infection could additionally be associated with the risk of nonmalaria fevers in infants. METHODS: From 2007 to 2009, 553 infants were followed up from birth to 18 months in Benin. The occurrence of fever was actively screened by trained community workers. Malaria fevers (temperature >37.5°C with positive results of rapid diagnostic test or thick blood smear) were excluded from analysis. The association between placental malaria infection and the number of total, gastrointestinal, and respiratory febrile episodes was explored using binomial negative regression, with adjustment for maternal age, parity, parents' schooling, socioeconomic level, sex, village of birth, season of birth, prematurity, Apgar score and nutritional status. RESULTS: The prevalence of placental malaria infection was 11.2%. During a median follow-up of 17.8 months, 624 nonmalaria fevers were registered. Placental malaria infection was associated with a higher risk of nonmalaria fever episodes (adjusted incidence rate ratio, 1.4; 95% confidence interval, 1.1-1.8) as well as gastrointestinal (1.6; 1.1-2.5) and respiratory (1.5; 1.1-2.1) febrile syndromes. The same pattern was obtained when considering consultations after the age of 6 months. CONCLUSIONS: These results suggest an association between placental malaria infection and nonmalaria infections in the first 18 months of life. Immune tolerance could lead to impaired immune development not specific to malaria infections in infants born to mothers with placental malaria infection, but further studies are needed.

Anaemia during pregnancy: impact on birth outcome and infant haemoglobin level during the first 18 months of life.

To determine the effect of maternal anaemia on pregnancy outcome and describe its impact on infant haemoglobin level in the first 18 months of life, we conducted a prospective study of 617 pregnant women and their children in Benin. Prevalence of maternal anaemia at delivery was 39.5%, and 61.1% of newborns were anaemic at birth. Maternal anaemia was not associated with low birth weight [OR = 1.2 (0.6-2.2)] or preterm birth [OR = 1.3 (0.7-2.4)], whereas the newborn's anaemia was related to maternal anaemia [OR = 1.8 (1.2-2.5)]. There was no association between an infant's haemoglobin level until 18 months and maternal anaemia. However, malaria attacks during follow-up, male gender and sickle cell trait were all associated with a lower infant haemoglobin level until 18 months, whereas good infant feeding practices and a polygamous family were positively associated with a higher haemoglobin level during the first 18 months of life.

Prematurity, intrauterine growth retardation and low birth weight: risk factors in a malaria-endemic area in southern Benin.

BACKGROUND: The aim of this study was to describe the contribution of prematurity and small for gestational age (SGA) to low birth weight (LBW) as well as to identify risk factors associated with preterm birth and SGA and to explore their impact on birth weight. METHODS: A cross-sectional study was carried out in southern Benin between June 2007 and July 2008. At delivery, women's characteristics and newborn's anthropometric measurements were collected. Gestational age was estimated using the Ballard method; SGA was defined using the William's reference curve. Analyses were performed by multiple logistic and linear regressions. RESULTS: In total, 526 mother-infant pairs were enrolled. LBW (<2500 g), prematurity (<37 weeks) and SGA accounted for 9.1%, 10.3% and 25.3% of the sample, respectively. Infant's male gender was associated with a lower risk of prematurity (p=0.03). Low maternal anthropometric status (p<0.001), primiparity (p=0.017) and infant's male gender (p=0.015) were associated with an increased risk of SGA. Only low maternal anthropometric status and primiparity were associated with an increased risk of LBW, and their effect on LBW was mediated by SGA. CONCLUSIONS: SGA was the main mechanism mediating the effect of risk factors on LBW. Maternal undernutrition (either short stature or low anthropometric status) was the most important of them.

Factors associated with growth patterns from birth to 18 months in a Beninese cohort of children.

The aim of this study was to analyze factors influencing the growth pattern of children from birth to 18 months. A longitudinal prospective study was conducted in three maternity wards in Southern Benin. Inclusion took place between June 2007 and July 2008; children were followed-up until 18 months of age. Height-for-age and weight-for-height Z-scores were computed using the newborn's anthropometric measurements taken at delivery, every month up to 6 months and then quarterly. Infant and young child feeding (IYCF) practices and malarial morbidity were recorded. Gestational age was estimated using the Ballard method; William's sex-specific reference curve of birth weight-for-gestational-age was used to determine intrauterine growth retardation (IUGR). Analyses were performed on 520 children using a linear mixed model. Low birth weight (coef=-0.43; p=0.002), IUGR (coef=-0.49; p<0.001), maternal short stature (coef=-0.25; p=0.001) and maternal low weight status (coef=-0.19; p=0.006) were significantly associated with growth impairment. Only LBW (coef=-0.28; p=0.05) and maternal low weight status (coef=-0.23; p=0.004) were associated with wasting. A good IYCF score was positively associated with weight gain (coef=0.14; p<0.001) whereas we found a paradoxical association with length (coef=-0.18; p<0.001). Malaria morbidity was not associated with growth. LBW, IUGR and maternal low weight status and height were important determinants of children's growth. These results reinforce and justify continuing public health initiatives to fight IUGR and LBW and break the intergenerational cycle of malnutrition.

Prevention of malaria during pregnancy: assessing the effect of the distribution of IPTp through the national policy in Benin.

The efficiency of malaria prevention during pregnancy was compared between three studies in Benin for malaria infection of the placenta (MIP) and low birth weight (LBW). The first was carried out when chloroquine prophylaxis was still recommended, the second was an intermittent preventive treatment in pregnancy (IPTp) clinical trial comparing sulfadoxine pyrimetamine (SP) versus mefloquine, and the third was an observational study after SP-IPTp national implementation. We showed an association between the use of IPTp and the reduction of LBW (10% with national IPTp and 8.7% in IPTp trial versus 15.7% in pre-trial study). The effect on MIP was better in the trial (2.9% versus 11.2% and 16.7% for national IPTp and pre-trial studies, respectively). In spite of a good overall compliance with the national IPTp (with 84% of women taking at least one dose of SP), there are still failures in adherence to the directly observed therapy (DOT) scheme and needs for better training of health staff.