Karna P
Department of Pediatrics, Michigan State University, East Lansing.
Am J Perinatol. 1991 Jul;8(4):288-91. doi: 10.1055/s-2007-999399.
If a low level of free thyroxine (T4) is predictive of the true hypothyroidism in sick premature infants, long-term developmental follow-up of these infants should reveal a direct correlation between the free thyroxine level early in life and developmental disability in later years. Half of the 16 infants who were followed had normal free T4 (0.8 ng/dl or higher) and the remaining 8 infants had a low free T4 (0.38 +/- 0.15 ng/dl) during the first 2 weeks of life. Infants with low free T4 were followed sequentially during their stay in the neonatal intensive care unit and all eight showed free T4 levels more than 0.8 ng/dl by 36 to 44 weeks postconceptional age without any thyroid replacement. At follow-up, all 16 infants were functioning within normal range by Stanford-Binet testing at mean age of 4.6 years. There was no significant difference between the two groups in their motor development, hearing, language, or physical growth. Despite the small sample size, it appears there is no correlation between the free T4 levels during the first 2 weeks of life in infants 33 weeks' or less gestation and their developmental outcome at mean age of 4.6 years.
如果低水平的游离甲状腺素（T4）可预测患病早产儿的真正甲状腺功能减退，那么对这些婴儿进行长期发育随访应能揭示生命早期的游离甲状腺素水平与晚年发育障碍之间存在直接关联。在接受随访的16名婴儿中，有一半在出生后的头两周内游离T4水平正常（0.8纳克/分升或更高），其余8名婴儿的游离T4水平较低（0.38±0.15纳克/分升）。游离T4水平较低的婴儿在新生儿重症监护病房住院期间接受了连续监测，所有8名婴儿在孕龄36至44周时，游离T4水平均超过0.8纳克/分升，且未接受任何甲状腺替代治疗。在随访时，所有16名婴儿在平均年龄4.6岁时通过斯坦福-比奈测试，各项功能均在正常范围内。两组婴儿在运动发育、听力、语言或身体生长方面没有显著差异。尽管样本量较小，但似乎孕龄33周及以下的婴儿在出生后头两周的游离T4水平与其在平均年龄4.6岁时的发育结果之间没有关联。
