How can the occurrence of delayed elevation of thyroid stimulating hormone in preterm infants born between 35 and 36 weeks gestation be predicted?

TY - JOUR

T1 - How can the occurrence of delayed elevation of thyroid stimulating hormone in preterm infants born between 35 and 36 weeks gestation be predicted?

AU - Heo, You Jung

AU - Lee, Young Ah

AU - Lee, Yun Jeong

AU - Lim, Youn Hee

AU - Chung, Hye Rim

AU - Shin, Seung Han

AU - Shin, Choong Ho

AU - Yang, Sei Won

PY - 2019/8/1

Y1 - 2019/8/1

N2 - Objective We evaluated frequency and risk factors of delayed TSH elevation (dTSH) and investigated follow-up outcomes in the dTSH group with venous TSH (v-TSH) levels of 6-20 mU/L according to whether late preterm infants born at gestational age (GA) 35-36 weeks had risk factors. Methods The medical records of 810 neonates (414 boys) born at Seoul National University Hospital who had a normal neonatal screening test (NST) and underwent the first repeat venous blood test at 10-21 days post birth were reviewed. Results Seventy-three (9.0%) neonates showed dTSH, defined as a v-TSH level .6.0 mU/L, 12 of whom (1.5%) were started on levothyroxine medication. A multivariate-adjusted model indicated that a low birth weight (LBW <2,000 g), a congenital anomaly, and exposure to iodine contrast media (ICM) were significant predictors for dTSH (all p < 0.05). Among these 73 dTSH infants, all 5 infants with TSH levels ≥20 mU/L began levothyroxine medication, and 6 of 16 infants with v-TSH levels of 10-20 mU/L were indicated for levothyroxine, regardless of coexisting risk factors. However, only 1 of 52 infants with v-TSH levels of 6-10 mU/L who had a congenital anomaly was indicated for levothyroxine. All healthy late preterm infants, including LBW and multiple births, with v-TSH levels of 6-10 mU/L exhibited normal thyroid function. Conclusions dTSH was detected in 9.0% and levothyroxine was indicated in 1.5% of infants born at GA 35-36 weeks, particularly those with a LBW, a congenital anomaly, or history of ICM exposure. Either levothyroxine or retesting is indicated for late preterm neonates with TSH levels ≥10 mU/L regardless of risk factors. If healthy preterm neonates show v-TSH levels of 6-10 mU/L, a second repeat test may not be necessary; however, further studies are required to set a threshold for retesting.

AB - Objective We evaluated frequency and risk factors of delayed TSH elevation (dTSH) and investigated follow-up outcomes in the dTSH group with venous TSH (v-TSH) levels of 6-20 mU/L according to whether late preterm infants born at gestational age (GA) 35-36 weeks had risk factors. Methods The medical records of 810 neonates (414 boys) born at Seoul National University Hospital who had a normal neonatal screening test (NST) and underwent the first repeat venous blood test at 10-21 days post birth were reviewed. Results Seventy-three (9.0%) neonates showed dTSH, defined as a v-TSH level .6.0 mU/L, 12 of whom (1.5%) were started on levothyroxine medication. A multivariate-adjusted model indicated that a low birth weight (LBW <2,000 g), a congenital anomaly, and exposure to iodine contrast media (ICM) were significant predictors for dTSH (all p < 0.05). Among these 73 dTSH infants, all 5 infants with TSH levels ≥20 mU/L began levothyroxine medication, and 6 of 16 infants with v-TSH levels of 10-20 mU/L were indicated for levothyroxine, regardless of coexisting risk factors. However, only 1 of 52 infants with v-TSH levels of 6-10 mU/L who had a congenital anomaly was indicated for levothyroxine. All healthy late preterm infants, including LBW and multiple births, with v-TSH levels of 6-10 mU/L exhibited normal thyroid function. Conclusions dTSH was detected in 9.0% and levothyroxine was indicated in 1.5% of infants born at GA 35-36 weeks, particularly those with a LBW, a congenital anomaly, or history of ICM exposure. Either levothyroxine or retesting is indicated for late preterm neonates with TSH levels ≥10 mU/L regardless of risk factors. If healthy preterm neonates show v-TSH levels of 6-10 mU/L, a second repeat test may not be necessary; however, further studies are required to set a threshold for retesting.

U2 - 10.1371/journal.pone.0220240 A

DO - 10.1371/journal.pone.0220240 A

M3 - Journal article

SN - 1663-2818

VL - 91

JO - Hormone Research in Paediatrics

JF - Hormone Research in Paediatrics

M1 - e0220240

ER -