Maternal Iodine Deficiency during Pregnancy and Child Growth to 5 Years of Age in Rural Bangladesh

Abstract

We examined associations between maternal gestational iodine status and growth to 5 years of age in 450 children in Gaibandha District, Bangladesh. Iodine status of women participating in a trial of vitamin A and beta‐carotene supplementation was assessed by urinary iodine excretion (UIE) early (<3rd trimester) and late (3rd trimester) in gestation. Growth variables at birth and ~60 months of age were weight (kg), length/height (cm), head circumference (HC, cm), their Z‐scores (WAZ, LAZ, HCAZ), and chest (CC, cm) and mid‐upper arm (MUAC, cm) circumferences. In multiple linear regression analyses, adjusting for confounders, children born to mothers with severe ID (UIE < 20μg/L) in late pregnancy were lighter in weight (β=−0.156 kg) and WAZ (β=−0.40), shorter in length (β=−0.81 cm) and LAZ (β=−0.43), and smaller in CC (β= −0.74 cm) at 5 years than children of mothers with adequate status (>100μg/L, p<0.05). UIE in early, but not late, pregnancy was positively associated with postnatal 5 year increments in weight (β=0.0023), WAZ (β=0.0016), height (β=0.0051), HAZ (β=0.0021) and HC (β=0.0018) (all p<0.05). Maternal iodine status, measured by gestational UIE, and reflecting iodine availability to the fetus, is a determinant of child growth over the first five years of life. Support: Gates Foundation, DSM Scholarship for International Micronutrient Research, USAID, Sight and Life Research Institute