Background: Thyroid hormones are essential for brain development. Transient hypothyroxinemia early in life may increase the risk of neurodevelopment disabilities in preterm infant.
Objectives: Examine the characteristics of thyroid function of preterm infants, and to determine the validity of a repeat thyroid function test for preterm infants.
Methods: This prospective comparative study was carried out during the period from Septemper 2016, to March 2017, at Al-Hussein University Hospital and Sohag General Hospital (neonatal care unit), done on 50 preterm neonates, their gestational age ranged from 34 to 36 weeks, (group 1), and 20 prterm neonates their gestational age less than 34 weeks,( group 2), on randomized base. Initial serum levels of free thyroxine (FT4), free triiodothyronine (FT3), and thyrotropin (TSH) were measured within the first 10 days of life and were repeated every 2 and 4 weeks after the first test. The study was carried out on either gender, delivered vaginally or by cesarean section, to apparently healthy mothers.This Study was carried out at Al-Hussein University Hospital and Sohag General Hospital (neonatal care unit). Factors related to the neonate as gestational age ,birth weight, sex and mode of delivary were studied in relation with the results of thyroid function tests.
Results: This study shows that 42 (84%) of preterm neonates in group1 have normal thyroid function test, and 3 (6%) have transient hypothyroxinemia, and 5 (10%) have transient TSH elevation. In group 2, our study shows that 13 (65%) of preterm neonates have normal thyroid function test and 3 (15%) have transient hypothyroxinemia and 5 (20%) have transient TSH elevation, the study shows no cases of congenital hypothyroidism in both (two) groups. Statistical analysis was done by using IBM SPSS software package version 20.0.Comparison between different groups regarding categorical variables was tested using Chi-squara test.
Conclusion: Although the study shows no statistical relation between gestational age and the weight of neonates with thyroid function test results, but there was statistically significant deference between the elevation in TSH and weight of neonates