妊娠合并甲状腺功能减退症孕妇的新生儿脐血甲状腺功能筛查的意义

目的 研究妊娠合并甲状腺功能减退症(甲减)者新生儿脐静脉血甲状腺功能检测的临床意义及其影响因素.方法 对67例在北京协和医院产科分娩的妊娠合并甲减行脐血甲状腺功能检查者进行回顾性分析.比较脐血与新生儿生后5～7 d静脉血的甲状腺功能及甲状腺自身抗体(抗-TGAb/抗-TPOAb)结果;分析甲状腺自身抗体水平在母血、脐血和新生儿生后5～7 d静脉血之间的相关性;并进一步分析脐血促甲状腺激素(thyroid stimulating hormone,TSH)的影响因素.TSH结果以中位数(第25～75百分位)表示.结果 (1)母亲患甲减时,新生儿脐血中TSH升高的比例为9.0%(6/67).(2)脐血TSH水平与新生儿生后5～7 d静脉血TSH水平无相关性.阴道分娩组脐血TSH显著高于剖宫产组[10.20 mU/L(6.10～12.80 mU/L)和5.86 mU/L(4.02～7.74 mU/L),P=0.001],胎儿窘迫或早产者脐血TSH分别高于无胎儿窘迫或足月产者[胎儿窘迫:10.36 mU/L(6.61～13.37 mU/L)和6.89 mU/L(4.18～9.70 mU/L),P=0.046;早产:8.90 mU/L(7.60～10.33 mU/L)和6.84 mU/L(4.17～9.80 mU/L),P=0.049].(3)脐血抗-TGAb和抗-TPOAb水平与新生儿5～7 d静脉血水平分别呈正相关(r分别=0.960和0.975,P均=0.000).母血抗-TGAb和抗-TPOAb水平对脐血的抗体结果有显著影响(P=0.003和0.000),但与新生儿TSH水平无关(P>0.05).结论 脐血TSH受多种分娩因素的影响,使其预测新生儿先天性甲减的意义受到影响.但母亲甲减时其新生儿脐血TSH水平升高和抗-TGAb及抗-TPOAb阳性的风险明显增加,成为其发生甲减的危险因素,因此,对这些新生儿需要进一步随访.

Thyroid function screening of cord blood in infants born to mothers complicated with hypothyroidism during pregnancy

Objective To evaluate the clinical significance of thyroid stimulating hormone (TSH) and thyroid autoantibodies (anti-TGAb and anti-TPOAb) in cord blood of infants of mothers complicated with hypothyroidism and the influencing factors of neonatal thyroid function. Methods Clinical data of 67 singleton pregnant women complicated with hypothyroidism in Peking Union Medical College Hospital were analyzed retrospectively. Thyroid function and its autoantibody levels in maternal, cord blood and neonatal serum at 5-7 d after birth were compared. Umbilical TSH level and its affecting factors were also investigated. The results of TSH was expressed as median (25th-75th percentile). Results (1) Umbilical TSH levels were elevated in 9. 0% (6/67) of all infants born to mothers complicated with hypothyroidism. (2) No correlation was found in TSH levels between cord blood and venous blood in neonates 5-7 d after birth. Umbilical TSH levels were significantly higher in infants born vaginally than in those born abdominally [10. 20(6. 10-12. 80) mU/L vs 5. 86(4.02-7.74) mU/L,P=0.001]. Higher umbilical TSH levels were also detected in those complicated with fetal distress and preterm birth compared with those withoutere [fetal distress: (10. 36(6. 61-13. 37) mU/L and 6. 89(4. 18-9. 70) mU/L, P = 0. 046; preterm birth: 8. 90(7. 60-10. 33) mU/L and 6.84(4.17-9. 80) mU/L,P=0. 046,0. 049)]. (3) The anti-TGAb levels in cord blood were positively correlated with that in neonatal serum at 5-7 d after birth (r=0. 960, P = 0. 000), and the same was true for anti-TGPOAb levels (r= 0. 975, P = 0. 000). Maternal thyroid autoantibody levels (anti-TGAb and anti-TPOAb) had significant effect on umbilical antibody levels (P = 0. 003 and 0. 000, respectively), but not on the neonatal TSH levels (P>0. 05). Conclusions Umbilical TSH levels are affected by many delivery factors which may limit its prediction role on congenital hypothyroidism. However, there is an increased risk of elevated umbilical TSH, anti-TGAb and anti-TPOAb levels among these patients which may increase the risk of congenital hypothyroidism. Further follow up of these infants is warranted.