Iodine Deficiency as Assessed by Neonatal TSH in a Sample of Mother-and-Newborn Pairs in Jiangsu Province, China

China has eliminated iodine deficiency disorders since 2011 via the implementation of universal salt iodisation. Following this, a new revised salt iodisation policy was introduced to reduce iodine content in table salt. Since maternal iodine deficiency can lead to cognitive impairment and cretinism in infants, the aim of our study was to assess if the iodine status of pregnant women and neonates was affected by the introduction of new salt iodisation policy. The medical records of the pregnant women and their neonates in the Northern Jiangsu People’s Hospital, Yangzhou, Jiangsu Province, China, between January 2018 and May 2018 were reviewed and obtained. Our study included 374 mother-and-newborn pairs. Mean age of the participants was 28 ± 4 years. TSH, FT3 and FT4 of the participants remained within the reference range. The prevalence of thyroid dysfunction was 4.3%. The overall mean neonatal TSH, birth weight and prevalence of low birth weight (LBW) was 2.56 ± 1.59 mIU/L, 3348 ± 465 g and 2.4%, respectively. The prevalence of neonatal TSH values > 5 mIU/L was 8.3%, which suggested the emergence of mild iodine deficiency (i.e. 3.0–19.9%) in our province. In conclusion, although our study reported an improvement of iodine status to mild iodine deficiency in 2017, our pregnant women remained to be iodine deficient. We recommended an ongoing monitoring of iodine status and advocate for the routine iodine supplementation together with iodised salt in Chinese pregnant women.