Relationship between Different Iodine Status during Pregnancy and Infantile Physical Development in China - Abstract
Background: Maternal iodine status is an important public health issue worldwide because it is unequivocally important for offspring’s growth and development. While the effect of mild iodine deficiency/excessive during pregnancy on their infants’ physical growth is still uncertain and further studies are needed to conform it. Methods: This prospective study used Tianjin and Wuqiang registers of pregnant women and their 18-24 months infants, 2016 to 2018. Blood and urine samples from each mother-infant pair were collected to determine thyroid function and UIC. Infants’ weight, length and head circumference were measured. Results: A total of 469 mother-infant pairs were enrolled, including 245 boys (52.2%) and 224 girls (47.8%). Maternal and infants’ median UIC was 161 (111, 251) ?g/L and 217 (121, 361) ?g/L, both suggesting iodine sufficiency according to WHO/UNICEF /ICCIDD-recommended criteria. Only the head circumference for age (HFA) Z-scores in infants with UIC 100-149?g/L during pregnancy was above zero, and higher than those with UIC<100?g/L and 150-249?g/L (all P<0.05). No differences were found in Z-scores of length-for-age, weight-for-age and weight-for-length in infants with different maternal UIC during pregnancy, and no association was found between maternal thyroid function and infants’ physical growth. Conclusions: The HFA Z-score was higher in infants with maternal UIC 100-149 ?g/L, rather than 150-249?g/L, which imply that the criteria recommended by WHO/UNICEF/ ICCIDD may be a little high for Chinese pregnant women in such background of iodine nutrition.