Maternal iodine status during lactation and infant weight and length in Henan Province, China

Abstract

BackgroundInfants are very sensitive to iodine deficiency. Breastfed infants are dependent on maternal iodine intake. The aim of this study was to evaluate the relationship between maternal iodine status during lactation and infant weight and length.MethodsA cross-sectional survey was conducted to investigate maternal iodine status and infant anthropometric measures in Henan Province, China. Only exclusive breastfeeding mothers and their infants < 6 months of age (n = 747) were included in our final analysis. Urine samples were collected from all the mothers and infants. Infant weight and length were measured and converted into weight-for-age Z-score (WAZ) and height-for-age Z-score (HAZ) using the World Health Organization (WHO) AnthroPlus software.ResultsThe median urinary iodine concentration (UIC) in lactating women was significant lower than that in their infants (177.4 vs 261.1 μg/L, P < 0.001). A positive correlation was found between maternal and infant urinary iodine concentration (r = 0.203, P < 0.01). The mean HAZ and WAZ values were lowest in the infants whose mothers had UIC below 50 μg/L (n = 41). Infant WAZ with maternal UIC below 50 μg/L was significantly lower than those with maternal UIC of 50 μg/L or above (P = 0.043). After adjusting for confounding factors, there were significant differences in infant WAZ between maternal UIC groups.ConclusionsThe present study suggests that maternal iodine status during lactation may be related to their infant anthropometric index. Appropriate iodine intake of lactating women is beneficial for their infants.

Effects of Maternal Iodine Status during Pregnancy and Lactation on Maternal Thyroid Function and Offspring Growth and Development: A Prospective Study Protocol for the Ideal Breast Milk Cohort

“…To estimate the sample size, we considered the significance level and statistical power, and we estimated the ratio of the exposed to the unexposed from the results of previous studies [ 12 13 14 ]. According to a prospective study of 344 Korean pregnant women during their third trimester conducted among hospital-based participants, we calculated the ratio of the exposed to the unexposed by UIC levels [ 12 ].…”

Breast Milk Iodine Concentration Is Associated with Infant Growth, Independent of Maternal Weight

“…Postnatal growth studies are limited in both observational and iodine supplementation intervention studies during lactation [31]. In a study performed in China by Yang, a maternal iodine deficiency based on urinary iodine levels <50 µg/L during lactation was linked to a decreased infant WFA and LFA for infants <6 months of age, with positive effects of maternal iodine status on infant weight; however, BMIC was not measured to determine infant intake [1]. A review of survey data by Mason showed a positive relationship with iodine salt use and increased infant WFA and mid-upper-arm-circumference at 2 years.…”

“…Iodine is a key micronutrient required for adequate growth and development through its critical role in thyroid hormone synthesis [1]. Deficiency in iodine during the neonatal and infant periods may result in impairments in brain development, cognitive outcomes, motor function, and growth stunting.…”

“…Iodine studies in mother-infant cohorts have shown mixed results regarding birth anthropometric outcomes, with some studies associated with an increased mean birth weight with improved maternal iodine status [30][31][32][33][34]. Postnatal studies of iodine levels have shown an impact on growth factors but have not shown a consistent association with infant growth [1,31,[35][36][37][38].…”

Estratégias Dietéticas Para a Gestação E Lactação

“…Após o nascimento, o cérebro humano ainda está em crescimento e a maior parte do desenvolvimento desse órgão acontece antes que a criança atinja três anos de idade (PEREIRA, 2011), sendo o iodo fundamental para que isso aconteça de forma saudável. Os recém-nascidos são muito sensíveis à deficiência iódica, e após o nascimento, aqueles que estão em aleitamento materno exclusivo são dependentes da ingestão de iodo materna, sendo imprescindível que a lactante esteja com seus níveis de iodo dentro da faixa de normalidade (YANG et al, 2017b). Sabe-se que o hipotireoidismo congênito neonatal pode acarretar distúrbios graves como o cretinismo, que é o desenvolvimento de crianças com retardo mental, baixa estatura, mãos e pés edematosos e surdo-mudez (PÉON, 2015).…”