RESUMO
Objective To study the effect of maternal subclinical thyroid abnormalities [including subclinical hypothyroidism, hypothyroxinemia and positive anti-thyroid peroxidase antibody (TPOAb) with normal thyroid function] in women during 16-20 weeks of gestation on offspfing's intellectual development and motor function. Methods Sera from 1 268 women during 16-20 weeks of gestation (collected 2 years ago) were obtained and thyroid stimulating hormone (TSH), total thyroxine (TT4), free thyroxine (FT4) and TPOAb levels were measured. Pregnant specific thyroid function reference ranges were used to screen for subclinical hypothyroidism (18 cases), hypothyroxinemia (19 cases) and positive TPOAb (34 cases). From the same cohort, a total of 142 pregnant women who were euthyroid with negative TPOAb were selected as controls (a case: control ratio of 1 : 2). Intellectual and motor development score evaluations were performed in their children at 25-30 months of age. Results In the group of pregnant women with subclinical hypothyroidism, the offspring' s intelligence score was (109.89±13.81) points, which was 8.88 points lower than in the control group (P < 0.01). Similarly, the motor score of the offspring was (108.11±9.93) points, which was 9.98 points lower than in the control group (P < 0.01). In the pregnant women with hypothyroxinemia, the offspring's intelligence score was (112.32±15.10) points, 9.30 points lower than in the control group (P <0.01); the motor score was (112.21±12.26) points, 7.57 points lower than in the control group (P < 0.01). In the pregnant women with positive TPOAb and euthyroid function, the offspring's intelligence score was (112.70±20.64) points, 10.56 points lower than in the control group (P < 0.01); the motor score was (110.64±12.49) points, 9.03 points lower than in the control group (P < 0.01). Conclusion Maternal subclinical thyroid abnormality between 16-20 weeks of gestation adversely may affect offspring intellectual and motor development, suggesting the necessity for screening and treatment of maternal subclinical thyroid abnormality in the early stages of pregnancy.