Breast-fed infants of mothers who smoke incur iodine deficiency.

2004 MAR 4 - (NewsRx.com & NewsRx.net) -- Breast-fed infants of mothers who smoke incur iodine deficiency.

According to recent research published in the Journal of Clinical Endocrinology and Metabolism, "lack of iodine for thyroid hormone formation during the fetal stage and/or the first years of life may lead to developmental brain damage. During the period of breastfeeding, thyroid function of the infant depends on iodine in maternal milk. We studied healthy, pregnant women admitted for delivery and their newborn infants."

"Cotinine in urine and serum was used to classify mothers as smokers (n=50) or nonsmokers (n=90)," wrote P. Laurberg and colleagues, Aalborg Hospital, Department of Endocrinology and Medicine.

"Smoking and nonsmoking mothers had identical urinary iodine on day 5 after delivery, but smoking was associated with reduced iodine content in breast milk (smokers 26.0 microgram/liter vs. nonsmokers 53.8 microgram/liter; geometric mean, p

"Results were consistent in multivariate linear models and by logistic regression analysis. The odds ratio for smoking vs. nonsmoking mothers to have lower breast milk than urinary iodine content was 8.4 (95% confidence interval, 3.5-20.1). In smokers, iodine transfer into breast milk correlated negatively to urinary cotinine concentration," researchers said.

"Smoking mothers had significantly higher ...