Prevalence of Iodine Insufficiency Is High Among Pregnant and Lactating Women in Northern Bangladesh Three Decades After Initiating Mandatory Salt Iodization

Abstract

ObjectivesOptimum Iodine status during pregnancy and lactation is crucial for normal fetal growth and child development. We assessed the urinary iodine concentration of pregnant and lactating women to determine their iodine status and measured salt iodine from their households. MethodsWe collected spot urine samples and corresponding household salt samples from 80 pregnant women (37 and 43 second and third-trimester women, respectively) and 49 lactating women (with children <6 months). Urinary iodine was determined by manual digestion with ammonium persulfate followed by Sandell-Kolthoff Reaction using 96 multi-well plates and a micro-plate reader at 405 nm. The iodine content in salt was measured by iodometric titration method. Samples were analyzed at the icddr, b Immunology, Nutrition, and Toxicology Laboratory, Dhaka, Bangladesh. ResultsThe median [IQR] UIC in the second-trimester women, third-trimester women, and lactating women was 90.6[41.9–171.5] mcg/L, 67.9[24.2–144.5] mcg/L, and 74.7[48.1–134.8] mcg/L, respectively. More than three-quarters of pregnant women (73% of the second-trimester women and 79% of the third-trimester women) and more than half of the lactating mothers (57%) were below the WHO recommended cut-offs. Only 42% of the household salts were adequately iodized. A moderate positive linear relationship was found between urinary and household salt iodine content (r = 0.51, P < 0.0001). ConclusionsEven with mandatory salt iodization policy in Bangladesh for about three decades, the iodine insufficiency among pregnant and lactating women is widespread and needs to be improved through ensuring the availability of adequately iodized salt or supplement. Funding SourcesETH Zurich, Switzerland.