Longitudinal Assessment of Prenatal, Perinatal, and Early-Life Aflatoxin B1 Exposure in 828 Mother-Child Dyads from Bangladesh and Malawi

Joshua W Smith; Andrew J Matchado; Lee S-F Wu; Charles D Arnold; Sean M Burke; Kenneth M Maleta; Per Ashorn; Christine P Stewart; Saijuddin Shaikh; Hasmot Ali; Alain B Labrique; Keith P West Jr; Parul Christian; Kathryn G Dewey; John D Groopman; Kerry J Schulze

doi:10.1093/cdn/nzab153

Longitudinal Assessment of Prenatal, Perinatal, and Early-Life Aflatoxin B₁ Exposure in 828 Mother-Child Dyads from Bangladesh and Malawi

Curr Dev Nutr. 2022 Jan 7;6(2):nzab153. doi: 10.1093/cdn/nzab153. eCollection 2022 Feb.

Authors

Joshua W Smith¹, Andrew J Matchado², Lee S-F Wu³, Charles D Arnold², Sean M Burke¹, Kenneth M Maleta⁴, Per Ashorn⁵, Christine P Stewart², Saijuddin Shaikh³, Hasmot Ali³, Alain B Labrique³, Keith P West Jr³, Parul Christian³, Kathryn G Dewey², John D Groopman¹, Kerry J Schulze³

Affiliations

¹ Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
² Department of Nutrition and Institute for Global Nutrition, University of California, Davis, Davis, CA, USA.
³ Center for Human Nutrition, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
⁴ School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi.
⁵ Tampere University, Faculty of Medicine and Health Technology, Center for Child, Adolescent and Maternal Health Research and Tampere University Hospital, Department of Pediatrics, Tampere, Finland.

Abstract

Background: In utero or early-life exposure to aflatoxin, which contaminates staple crops in disadvantaged settings, may compromise pregnancy and infant outcomes, but investigations into the extent, persistence, and determinants of aflatoxin exposure at these life stages have lacked longitudinal data collection and broad geographic representation.

Objectives: Aflatoxin exposure and selected determinants thereof were characterized in mother-child dyads with serial plasma/serum samples in prenatal, perinatal, and early life in Malawi and Bangladesh.

Methods: Circulating aflatoxin B₁ (AFB₁)-lysine albumin adducts were measured in dyads from Bangladesh (n = 573; maternal first and third trimester, 3 mo postpartum, cord blood, infant 24 mo) and Malawi (n = 255; maternal second and third trimester, 6 mo postpartum, infant 6 and 18 mo) with isotope dilution mass spectrometry. We examined AFB₁-lysine adduct magnitude, persistence, seasonality, and associations with infant feeding, and estimated daily AFB₁ intake.

Results: Maternal AFB₁-lysine was higher in Malawi (98% detectable; median: 0.469, IQR: 0.225-1.027 pg/µL) than in Bangladesh (59%; 0.030, nondetectable [nd]-0.077 pg/µL). Although estimated dietary exposure in Malawi was temporally stable (648 ng AFB₁/day), estimated intake in Bangladesh was reduced by 94% between rainy and winter seasons (98 to 6 ng/day). AFB₁-lysine was low in cord blood from Bangladesh (15% detectable; 0.045, 0.031-0.088 pg/µL among detectable) and in Malawian infants at 6 mo of age (0.072, nd-0.236 pg/µL), but reached maternal concentrations by 18 or 24 mo (Bangladesh: 0.034, nd-0.063 pg/µL; Malawi: 0.370, 0.195-0.964 pg/µL). In Malawian infants, exclusive breastfeeding at 3 mo was associated with 58% lower AFB₁-lysine concentrations at 6 mo compared with other feeding modes (P = 0.010).

Conclusions: Among pregnant women, aflatoxin exposure was persistently high in Malawi, while lower and seasonal in Bangladesh. Infants were partially protected from exposure in utero and with exclusive breastfeeding, but exposures reached adult levels by 18-24 mo of age. The Bangladesh and Malawi trials are registered at clinicaltrials.gov as NCT00860470 and NCT01239693.

Keywords: aflatoxin; breastfeeding; cord blood; diet; infancy; mass spectrometry; pregnancy; seasonality; toxicology.

Associated data

ClinicalTrials.gov/NCT00860470
ClinicalTrials.gov/NCT01239693