Determinants of recent aflatoxin exposure among pregnant women in rural Zimbabwe

Aflatoxins (AFs) are toxic secondary metabolites of Aspergillus species that contaminate staple foods such as maize and groundnuts. AF exposure during pregnancy has been associated with adverse birth outcomes in limited-scale surveys in sub-Saharan Africa. The objective of this study was to describe the determinants of AF exposure, using urinary aflatoxin M1 (AFM1) biomarkers and data generated by the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial for rural Zimbabwean women in early pregnancy. Sanitation Hygiene Infant Nutrition Efficacy is a large, cluster-randomized community-based trial in Zimbabwe designed to investigate the independent and combined effects of nutrition and hygiene interventions on early child growth.

Urine samples collected from 1580 pregnant women in rural Zimbabwe at median gestational age of 13.9 wk were measured for AFM1. AFM1 was detected in 30% of samples (median of exposed, 162 pg AFM1/mg creatinine; range 30-6046 pg AFM1/mg). In multivariable ordinal logistic models, geographical location (p<0.001), seasonality (p < 0.001) and dietary practices (p = 0.011) were significant predictors of urinary AFM1.

This is the largest AF biomarker survey conducted in Zimbabwe, and demonstrated frequent exposure in pregnant women with clear temporal and spatial variability in AF biomarker levels.