由于甲状腺激素实际上不能通过胎盘,因此胎儿的脑发育依靠自身的甲状腺功能。出生时甲状腺激素的缺乏将导致严重的生理、生化、和精神缺陷。只有尽早补充甲状腺激素,才能纠正这些缺陷。甲状腺激素最显著的作用是在脑发育的临界期,即脑细胞停止分裂开始分化的时期。尽管新生儿甲状腺功能低 Because thyroid hormones can not actually cross the placenta, fetal brain development depends on their own thyroid function. The lack of thyroid hormone at birth leads to serious physical, biochemical, and mental deficiencies. Only the early replacement of thyroid hormones, to correct these deficiencies. The most prominent role of thyroid hormones is in the critical stage of brain development, that is, the period when brain cells stop dividing and begin to differentiate. Although neonatal hypothyroidism