左旋甲状腺素治疗妊娠期TPO-Ab阴性亚临床甲状腺功能减退症的研究进展

Research Progress of Levothyroxine Treatment on TPO-Ab Negative Subclinical Hypothyroidism during Pregnancy

妊娠期亚临床甲状腺功能减退症(subclinical hypothyroidism,SCH)临床症状隐匿或无症状,临床上易被忽略,但发病率却不低。其可导致流产、早产、胎盘早剥、低出生体质量儿、妊娠期糖尿病等不良妊娠结局。尽管SCH妊娠妇女血清游离甲状腺素(free thyroxine,FT4)水平正常,但胚胎或胎儿组织中的FT4利用率却降低,表明正常范围内的FT4并不足以充分发挥作用。左旋甲状腺素(L-T4)是治疗SCH的首选药物,因其结构与人体的甲状腺激素相同,因此L-T4可通过增强酶活性、促进蛋白酶的合成从而影响胚胎和新生期细胞的生长、发育和分裂,同时L-T4也对妊娠妇女的体温调节、能量代谢、糖类、蛋白质和脂肪代谢等有显著的调节作用。关于妊娠期甲状腺过氧化物酶抗体(TPO-Ab)阴性SCH患者给予L-T4治疗能否降低流产率和其他并发症尚有争议。现就L-T4治疗妊娠期TPO-Ab阴性SCH的研究进展进行综述。

Subclinical hypothyroidism(SCH)in pregnancy is insidious or asymptomatic and easy to be ignored.It may lead to miscarriage,premature delivery,placental abruption,low birth weight,gestational diabetes and other adverse pregnancy outcomes.Although serum free thyroxine(FT4)levels were normal in women with SCH pregnancy,the utilization of FT4 in fetal or fetal tissues was decreased,suggesting that FT4 in the normal range is not sufficient to fully play its role.L-thyroxine(L-T4)is the first choice in the treatment of SCH.Because its structure is the same as human thyroid hormone,L-T4 can affect the growth,development and division of embryonic and neonatal cells by enhancing enzyme activity and promoting the synthesis of protease.At the same time,L-T4 also has a significant regulatory effect on body temperature regulation,energy metabolism,carbohydrate,protein and fat metabolism of pregnant women.Whether L-T4 treatment can reduce the abortion rate and other complications in pregnant women with negative thyroid peroxidase antibody(TPO-Ab)is still controversial.This article reviews the research progress of L-T4 in the treatment of TPO-Ab negative hypothyroidism in pregnancy.