Department of Pediatrics, Southern Medical College & Hospital, Southern Medical College Road, East Nasirabad, Khulshi, Chittagong, Bangladesh.
Department of Pediatrics, Doctor MR Khan Shishu Hospital, Mirpur, Dhaka, Bangladesh.
Indian J Pediatr. 2019 Aug;86(8):686-691. doi: 10.1007/s12098-019-02935-2. Epub 2019 Apr 3.
To determine whether hypothyroxinemia in the early neonatal period normalizes by 7 wk of postnatal age.
An observational study was carried out from July 2008 through June 2010 in the neonatal and postnatal unit of Chittagong Medical College Hospital, Bangladesh. A total of 150 neonates including 100 preterm and 50 term neonates were selected by convenient sampling. Preterm neonates were stratified according to postconceptional age. By the 3rd generation two site chemiluminesent immunometric assay, free T4 (FT) and thyroid stimulating hormone (TSH) estimations were done. Within 5-11 d, first samples were collected from all the neonates and the second samples of hypothroxinemic preterm neonates were collected within 42-50 d of birth.
Positive correlation of FT was found with gestational age (p < 0.0001, n = 100, r = 0.61) in preterm neonates while significant difference was found among the gestational age subgroups (p = 0.0001). No significant differences were, however, found in TSH levels of such age groups of the preterms. Highly significant differences in FT and TSH levels between 1st and 2nd samples were found in subgroup analysis of the preterm neonates. In the 1st samples, TSH level correlated positively with gestational age but in the 2nd samples, significant negative correlation was observed. In all neonates with initial hypothyroxinemia, FT levels were found to increase to reach the normal levels by 7 wk.
FT level normalizes by 7 wk of birth in preterm newborn neonates.
确定新生儿早期的甲状腺功能减退症是否在出生后 7 周内恢复正常。
本研究为 2008 年 7 月至 2010 年 6 月在孟加拉国吉大港医学院附属医院新生儿和产后病房进行的一项观察性研究。通过便利抽样，共选择了 150 名新生儿，包括 100 名早产儿和 50 名足月儿。根据受孕年龄对早产儿进行分层。采用第三代双位点化学发光免疫测定法检测游离 T4（FT）和促甲状腺激素（TSH）。所有新生儿在出生后 5-11 天内采集第一次样本，而甲状腺功能减退的早产儿在出生后 42-50 天内采集第二次样本。
FT 在早产儿中与胎龄呈正相关（p<0.0001，n=100，r=0.61），而不同胎龄亚组之间存在显著差异（p=0.0001）。然而，这些早产儿的 TSH 水平在各年龄组之间没有显著差异。在早产儿亚组分析中，FT 和 TSH 水平在第一次和第二次样本之间存在显著差异。在第一次样本中，TSH 水平与胎龄呈正相关，但在第二次样本中，观察到显著的负相关。在所有最初甲状腺功能减退的新生儿中，FT 水平增加到 7 周时达到正常水平。
早产儿的 FT 水平在出生后 7 周内恢复正常。
