[Correlation of congenital hypothyroidism with birth weight and gestational age in newborn infants].

OBJECTIVE

To investigate the correlation of congenital hypothyroidism (CH) with birth weight and gestational age in newborn infants.

METHODS

The screening of CH was conducted in all the live births in 2005 of Zhejiang Province, the blood samples were collected from heel stick. The thyroid stimulating hormone (TSH) was measured by time-resolved fluorescence immunoassay (TRFIA). If TSH was>9.0 mU/L, the infant was recalled for further examination.

RESULTS

A total of 387,926 infants were screened in 2005, of whom 289 cases were identified with CH. The prevalence rate was 1/1,342. Among the 289 CH cases, the prevalence of premature infants, term infants and post term infants were 1/1,454, 1/1,469 and 1/246, respectively. The CH prevalence of post term infants was significantly higher than that in other two groups (P<0.01). The prevalence of low birth weight infants, normal weight infants and macrosomia was 1/575, 1/1,505 and 1/473, respectively. The prevalence of low birth weight infants and macrosomia was significantly higher than that of normal weight group (P<0.01).

CONCLUSION

The prevalence of CH is associated with the birth weight and gestational age. To reduce the prevalence of CH in children, it is crucial to prevent post term, low birth weight, and macrosomia cases.