Maternal iodine nutrition during late pregnancy and neonatal physical development / 中华临床营养杂志

ABSTRACT

Objective:To monitor iodine nutrition of women during late pregnancy and examine the correlation between maternal urine iodine concentration and newborn physical development.Methods:Prospective cohort study was conducted in 151 pregnant women at 28-34 weeks' gestation who accepted nutrition follow-up between December 2014 and August 2015. Participants were surveyed twice at enrollment and hospitalization for delivery respectively by iodine related food frequency method and 24 h diet diary and dietary nutrition software was used to calculate diet iodine consumption amount. Spot urine samples were taken three times totally every two weeks and data of antenatal care was recorded and the participants were divided into groups during this period. The physical development indexes and neonatal thyroid stimulating hormone (TSH) levels were obtained.Results:Maternal median urinary iodine concentration was 100.0 μg/L. Using urinary iodine levels 150 μg/L and 249 μg/L as cut-off points, participants were divided into three subgroups as iodine-insufficient, iodine-adequate and iodine-over, with incidences of 76.8% ( n=116), 19.2% ( n=29), and 4.0% ( n=6), respectively. Subgroup analysis showed no significant differences between the iodine-insufficient group ( n=116) and the iodine-sufficient group ( n=35) in neonatal weight [(3 295±370) vs (3 395±450)g, P=0.183], neonatal length [50.0(48.0, 50.0) vs 50.0(49.0, 51.0)cm, P=0.171], neonatal head circumference [34.5 (34.0, 35.0) vs 34.5(34.0, 35.0)cm, P=0.691], or neonatal thyroid stimulating hormone levels [(4.0±1.9) vs (4.2±2.5)mIU/L, P=0.438]. Conclusions:According to World Health Organization criteria, iodine deficiency rate in women during late pregnancy reaches 76.8%. In this study there is no significant difference in newborn physical development indexes among various pregnancy iodine nutrition statuses.