Abstract: Objective To investigate the clinical features of neonates and mothers on the screening of congenital hypothyroidism (CH), and to provide a basis for avoiding the missed diagnosis of CH. Methods A total of 206 neonates with positive thyroid stimulating hormone (TSH) screening were collected from January 2016 to November 2017, and 206 neonates with negative TSH were randomly selected over the same period as normal control group according to 1∶1 ratio. The impact of neonatal sex, gestational age, body weight and maternal comorbidity on CH screening and diagnosis was analyzed in the two groups. Results The body weight of neonates with positive TSH screening was lower than that of normal newborn infants (P＜0.05), while there were no significant differences in sex, gestational age, the proportion of preterm, mature and post-term delivery between two groups. Compared with normal TSH screening, the proportion of mother with hypothyroidism and TSH level was significantly higher in screening positive group, but FT3 and FT4 levels were lower (P＜0.05). There were no significant differences in the ratio of gestational diabetes mellitus, anemia, subclinical hypothyroidism and hyperthyroidism, hemoglobin and fasting glucose between the two groups of mothers. Compared with confirmed normal group (n=198), the body weight was lower in confirmed CH group (n=8), and the proportion of mother with hypothyroidism and TSH level was significantly higher in confirmed CH group, FT3 and FT4 levels were lower (P＜0.05). There were no significant differences in sex, gestational age, the ratio of subclinical hypothyroidism and hyperthyroidism between CH group and confirmed normal group. Conclusion Neonatal low body weight and maternal hypothyroidism significantly affect the screening and diagnosis of CH. Special attention should be paid to clinical screening of CH in order to avoid missed diagnosis.

Key words: congenital hypothyroidism, neonatal screening, thyrotropin