In congenital hypothyroidism bone maturation at birth may be a predictive factor of psychomotor development during the first Year of life irrespective of other variables related to treatment

Abstract

Objective: To evaluate in a cohort of infants with congenital hypothyroidism (CH): (a) the frequency of bone maturation (BM) retardation at birth and (b) whether BM delay at birth may be considered as a tool to make a prognosis of psychomotor status at the age of 1 year, irrespective of other variables related to treatment. Design: BM at birth, CH severity and developmental quotient (DQ) at the age of 1 year were retrospectively evaluated in 192 CH infants selected by the following inclusion criteria: (a) gestation age ranging between 38 and 42 weeks; (b) onset of therapy within the first month of life; (c) initial thyroxine (L-T 4 ) dosage ranging from 10 to 12 mg/kg/day; (d) normalization of serum thyrotropin (TSH) levels before the age of 3 months; (e) monthly adjustments of L-T 4 dose during the first year of life with serum TSH levels ranging from 0.5 to 4 mIU/l; (f) no major diseases and/or physical handicaps associated with CH; (g) availability of both thyroid scanning and knee X-rays at the time of treatment initiation; (h) availability of DQ assessment at an average age of 12 months. Methods: BM was considered normal if the distal femur bony nucleus diameter exceeded 3 mm (group A) or retarded if either this nucleus was absent (subgroup B1) or its diameter was , 3 mm (subgroup B2). DQ was evaluated with the Brunet -Lézine test. Results: In 44.3% of cases BM was either delayed (23.5%) or severely delayed (20.8%). The risk of BM retardation was higher in the patients with athyreosis than in the remaining patients (41/57 vs 44/135, x 2 ¼ 25.13, P , 0.005). BM-retarded infants showed a more severe biochemical picture of CH at birth and a lower DQ at the age of one year compared with the group A patients. If compared with infants of subgroup B2 those of subgroup B1 exhibited significantly lower T 4 levels at birth and a more frequent association with athyreosis (70.0 vs 30.0%; x 2 ¼ 7.49, P , 0.01), whereas DQ was superimposable in both subgroups. Conclusions: (a) BM at birth is delayed in almost half of CH patients and (b) CH severity per se can affect DQ at the age of 1 year irrespective of other variables related to therapy.

Management of neonates born to women with Graves' disease: a cohort study

“…Echocardiography was done in 60 of the 68 patients. Bone maturation was assessed by a routine knee radiograph at birth and classified as advanced, delayed, or normal (29). Cranial radiographs were obtained routinely to look for craniosynostosis.…”

Risk factors for neurodevelopmental deficits in congenital hypothyroidism after early substitution treatment

“…Bone age was determined from X-rays of the knees of newborn infants (before or 1-3 days after the start of therapy) and was defined as normal if its diameter exceeded 3 mm or retarded when the bony nucleus of the distal femoral epiphysis was absent or its diameter was < 3 mm in children born full term or with corrected gestational age of more than 37 weeks [18]. Of the 155 included cases, knee X-rays were conducted in 124 cases.…”

Psychological and behavioural aspects in children and adolescents with congenital hypothyroidism diagnosed by neonatal screening: comparison between parents' and children's perceptions

“…We examined 84 consecutive CH children and adolescents (33 males) with chronological age (CA) The CH patients were classified into two subgroups: 'severe CH' and 'moderate/mild CH', according to bone maturation at birth evaluated by X-ray assessment of the distal femoral epiphyseal ossification centre at the confirmation of diagnosis (severe CH: bony nucleus absent or its diameter !3 mm; moderate/mild CH: bony nucleus diameter R3 mm) (20). This indicator of prenatal CH severity was preferred to neonatal FT 4 cutoff level according to pre-therapy serum FT 4 concentration (21), because it was considered a more reliable indicator of foetal thyroid hormone supply during the pregnancy (10,11,20).…”

“…This indicator of prenatal CH severity was preferred to neonatal FT 4 cutoff level according to pre-therapy serum FT 4 concentration (21), because it was considered a more reliable indicator of foetal thyroid hormone supply during the pregnancy (10,11,20). However, Table 1 shows that bone maturation at birth was related to FT 4 serum levels at confirmation; therefore, they were both good parameters for the estimation of prenatal CH severity.…”