Association between placental malaria, postnatal linear growth, and body mass index in the Dogon Longitudinal Study, Mali.

BACKGROUND

Malaria is a primary cause of morbidity and mortality in Mali, with women at high risk for malaria infection during pregnancy. Placental malaria (PM) has been linked to adverse neonatal outcomes such as low birth weight, decreased birth length, and decreased placental weight, but few studies have tested for associations between PM and postnatal growth. This study examined the relationship between PM and linear growth, weight, and body mass index (BMI) from birth to age 5 years.

METHODS

The study participants (N = 317) were members of the F2 generation of the Dogon Longitudinal Study, a multigenerational prospective cohort study conducted in the District of Bamako and on the Bandiagara Escarpment in central Mali. Placental samples were collected for each participant and evaluated by histology to determine PM infection stage and parasite density. Participant's height, weight, and BMI were measured approximately twice per year from birth until a median age of 6.8 years (maximum age 12.3 years). Linear mixed models were used to investigate the relationship between PM and height, weight, and BMI from birth to age 5 years.

RESULTS

Linear growth in height at age 6 months was lower in infants from placentas with severe parasite density compared to infants from placentas in which no parasites were detected (-0.83 cm; 95% CI -1.63, - 0.03; p = 0.042), with a trend of decreased height continuing to age 5 years. Severe parasite density was also associated with a statistically significant increase in BMI at 2 years (0.56 kg/m2; 95% CI 0.13, 1.00; p = 0.011), 3 years (0.82 kg/m2; 95% CI 0.35, 1.30; p = 0.001), 4 years (1.09 kg/m2; 95% CI 0.53, 1.65; p > 0.001), and 5 years (1.35 kg/m2; 95% CI 0.68, 2.01; p > 0.001) of age when controlling for birth weight. No statistically significant associations were observed between parasite density and weight.

CONCLUSIONS

Severe malaria parasite density in the placenta was associated with birth length, as shown in previous studies, and, in addition, was associated with decreased linear growth to age 5 years. Moreover, this study provided the first evidence that PM is associated with increased postnatal BMI.