Fetal Environment Is a Major Determinant of the Neonatal Blood Thyroxine Level: Results of a Large Dutch Twin Study.

Context: The interindividual variability in thyroid hormone function parameters is much larger than the intraindividual variability, suggesting an individual set point for these parameters. There is evidence to suggest that environmental factors are more important than genetic factors in the determination of this individual set point.

Objective: This study aimed to quantify the effect of genetic factors and (fetal) environment on the early postnatal blood T4 concentration.

Evaluation of cognitive and motor development in toddlers with congenital hypothyroidism diagnosed by neonatal screening.

Objective: The Dutch neonatal congenital hypothyroidism (CH) screening procedure and treatment modality has been adapted several times since its national institution in 1981. These changes enabled us to investigate whether earlier treatment has resulted in improved cognitive and motor outcomes. The present study examined whether the advancement of treatment modality has resulted in improved cognitive and motor outcomes.

The effect of life-long thyroxine treatment and physical activity on bone mineral density in young adult women with congenital hypothyroidism.

Objective: Normalization of plasma thyrotropin in T4-supplemented patients with thyroidal congenital hypothyroidism (CH) requires elevated plasma FT4-concentrations compared to patients with acquired thyroidal hypothyroidism. We investigated bone mineral density (BMD) in patients with CH.

Patients And Methods: BMD was measured in 14 adult women with thyroidal CH and nine age-matched female controls.

Neonatal screening for congenital hypothyroidism in the Netherlands: cognitive and motor outcome at 10 years of age.

Context: Patients with thyroidal congenital hypothyroidism (CH-T) born in The Netherlands in 1981-1982 showed persistent intellectual and motor deficits during childhood and adulthood, despite initiation of T(4) supplementation at a median age of 28 d after birth.

Objective: The present study examined whether advancement of treatment initiation to 20 d had resulted in improved cognitive and motor outcome.

Design/setting/patients: In 82 Dutch CH-T patients, born in 1992 to 1993 and treated at a median age of 20 d (mean, 22 d; range, 2-73 d), cognitive and motor outcome was assessed (mean age, 10.