Yixin Zhang1, Cong Du1, Wei Wang1, Wen Chen1, Ping Shao2, Chongdan Wang3, Junhong Leng2, Jun Shen4, Long Tan1, Wanqi Zhang5. 1. Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China. 2. Department of Maternal and Child Health, Tianjin Maternal and Child Health Center, Tianjin, China. 3. Department of Obstetrics, Tanggu Maternity Hospital, Tianjin, China. 4. Department of Sanitary Chemistry, Tianjin Medical University, Tianjin, China. 5. Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China. Electronic address: wqzhang@tmu.edu.cn.
Abstract
OBJECTIVE: Neonatal TSH screening is effective in detecting congenital hypothyroidism and estimating iodine status in a given population, but various factors influence TSH levels. The aim of this study was to evaluate the effect of maternal and neonatal factors on neonatal TSH levels. DESIGN AND SETTING: Data were obtained from an ongoing prospective cohort study. A total of 988 pregnant women and their newborn infants participated in the study from April 2015 to May 2017 at Tianjin Maternal and Child Health Center and Tanggu Maternity Hospital in Tianjin, China. Maternal demographic information, including age, height, and parity, was recorded by questionnaire. Fasting blood and urinary samples were collected from all pregnant women. After parturition, information on gestation duration, mode of delivery, neonatal sex, neonatal TSH, neonatal birth weight, and neonatal birth height were recorded. RESULTS: Maternal age, maternal BMI, gestation duration, parity, and neonatal birth weight and height were significantly correlated with neonatal TSH (p < 0.05). Quantile regression revealed that maternal age, TSH, FT4, and gestation duration were positively correlated with neonatal TSH level. A logistic regression model identified maternal BMI, TSH, and birth height as risk factors for having neonatal TSH > 5 mIU/L (p < 0.05). CONCLUSION: Neonatal TSH levels are dynamic and may be affected by several maternal and neonatal factors including maternal age, TSH, FT4, and birth weight and height. Identification of these confounders is useful for assessing the status of neonatal thyroid development. STRENGTHS AND LIMITATIONS OF THIS STUDY: (1) Iodine deficiency disorder has generally been eliminated, so the median urinary iodine concentration of pregnancy is higher than 150 μg/L even in mildly or moderately iodine deficient areas. (2) Unlike many other studies, which did not consider the complexity of factors or examined only one or two variables, this study used a multivariate model to analyze the data. (3) This study examined numerous high-risk factors in pregnant women and considered the biological interrelation between them. Future studies should consider these confounding factors for neonatal TSH levels and establish a proper neonatal TSH range for monitoring the iodine status of a population or diagnosing congenital hypothyroidism.
OBJECTIVE: Neonatal TSH screening is effective in detecting congenital hypothyroidism and estimating iodine status in a given population, but various factors influence TSH levels. The aim of this study was to evaluate the effect of maternal and neonatal factors on neonatal TSH levels. DESIGN AND SETTING: Data were obtained from an ongoing prospective cohort study. A total of 988 pregnant women and their newborn infants participated in the study from April 2015 to May 2017 at Tianjin Maternal and Child Health Center and Tanggu Maternity Hospital in Tianjin, China. Maternal demographic information, including age, height, and parity, was recorded by questionnaire. Fasting blood and urinary samples were collected from all pregnant women. After parturition, information on gestation duration, mode of delivery, neonatal sex, neonatal TSH, neonatal birth weight, and neonatal birth height were recorded. RESULTS: Maternal age, maternal BMI, gestation duration, parity, and neonatal birth weight and height were significantly correlated with neonatal TSH (p < 0.05). Quantile regression revealed that maternal age, TSH, FT4, and gestation duration were positively correlated with neonatal TSH level. A logistic regression model identified maternal BMI, TSH, and birth height as risk factors for having neonatal TSH > 5 mIU/L (p < 0.05). CONCLUSION: Neonatal TSH levels are dynamic and may be affected by several maternal and neonatal factors including maternal age, TSH, FT4, and birth weight and height. Identification of these confounders is useful for assessing the status of neonatal thyroid development. STRENGTHS AND LIMITATIONS OF THIS STUDY: (1) Iodinedeficiency disorder has generally been eliminated, so the median urinary iodine concentration of pregnancy is higher than 150 μg/L even in mildly or moderately iodine deficient areas. (2) Unlike many other studies, which did not consider the complexity of factors or examined only one or two variables, this study used a multivariate model to analyze the data. (3) This study examined numerous high-risk factors in pregnant women and considered the biological interrelation between them. Future studies should consider these confounding factors for neonatal TSH levels and establish a proper neonatal TSH range for monitoring the iodine status of a population or diagnosing congenital hypothyroidism.
Authors: Brett T Doherty; Noelle Kosarek; Andy N Hoofnagle; Yingying Xu; R Thomas Zoeller; Kimberly Yolton; Aimin Chen; Bruce P Lanphear; Joseph M Braun; Megan E Romano Journal: Clin Endocrinol (Oxf) Date: 2020-01-19 Impact factor: 3.478