26 METHODS FOR BONE MATURITY ASSESSMENT TO EVALUATE PRENATAL HYPOTHYROIDISM

Delayed skeletal maturation in newborn infants with congenital hypothyroidism (CH) is considered to reflect the degree of intrauterine hormone deficiency. Bone development was assessed by X-ray during the first month of life in 63 infants who had positive screening tests for CH. Serum hormone analysis confirmed the diagnosis in 46 infants while the remaining 17 infants were euthyroid at follow-up. Therapy was initiated in CH patients at the same age as radiograms were taken: 14.5±5.7 (x±SD) vs 15.0±5.5 days. Five radiographic methods to assess skeletal, development (including Senecal et al. (Arch Fr Ped. 34 (1977) 424) were tested for their capacity to distinguish CH patients from euthyroid infants. The various methods involved assessment of the shape and size of ossification centers in the knee and ankle regions. All five methods revealed statistically significant retarded bone maturity in CH infants (Mann-Whitney U test; p<0.001) and can be use to distinguish CH patients from euthyroid neonates. However, one of the tested methods, based on assessment of bone centers in the knee region only, has the advantage of convenience and is therefore to be recommended for routine use.