Effect of maternal and neonatal factors on cord blood thyroid stimulating hormone

Abstract

Background: Congenital hypothyroidism (CH) is most common preventable cause of mental retardation in children. Cord blood Thyroid Stimulating Hormone (CBTSH) level is an accepted screening tool for CH. Objectives: To study CBTSH profile in neonates born at tertiary care referral center and to analyze the influence of maternal and neonatal factors on their levels. Design: Cross retrospective sectional study. Methods: Study population included 979 neonates (males = 506 to females = 473). The CBTSH levels were estimated using electrochemiluminescence immunoassay on Cobas analyzer. Kit based cut-offs of TSH level were used for analysis. All neonates with abnormal CBSTH levels, were started on levothyroxine supplementation 10 μg/Kg/day and TSH levels were reassessed as per departmental protocol. Results: The mean CBTSH was 7.82 μIU/mL (Range 0.112 to 81.4, SD = 5.48). The mean CBTSH level was significantly higher in first order neonates, neonates delivered by assisted vaginal delivery and normal delivery, delivered at term or preterm, neonates with APGAR score 16.10 and 16.1 μIU/mL was significantly higher in neonates delivered by assisted vaginal delivery and normal delivery, term and preterm neonates, APAGR score of 16.10 and <1.0 led to a recall of 5.41% of neonates which is practicable given the scenario in our Country. The mode of delivery and perinatal stress factors have a significant impact on CBTSH levels and any rise to be seen in the light of these factors. The prevalence rate of CH after recall was ~3 in 1000 live births.

Keywords

• Cord blood thyroid stimulating hormone
• congenital hypothyroidism
• newborn screening