[Alpha fetoprotein in congenital hypothyroidism before and during treatment].

Background: Screening for congenital hypothyroidism (CH) is an opportunity to investigate maturation by measuring alphafetoprotein (AFP).

Patients And Methods: Blood AFP was measured in 73 full-term infants (controls), 22 infants with permanent CH and 19 with a transient form (FT) of hypothyroidism. It was also measured in mothers of the two groups with hypothyroidism. AFP was measured by RIA and its value was compared to those of FT4, TSH and bilirubin.

Results: Blood AFP was higher in patients with CH with significant differences between patients who had jaundice or not, but AFP was not significantly different in FT patients and controls. Initial values of AFP in both CH and FT population was correlated to the levels of AFP in their mothers. Under treatment with 7.5 micrograms/kg/day of l-T4, AFP levels remained increased at T15, then gradually normalized at T30-T60. The log of AFP was correlated to TSH levels between T15 and T60 but was not correlated to FT4 levels. Preliminary results at one year of age show that IQ seems better in infants with early normalization of AFP.

Conclusions: Prolonged follow-up is necessary to assess the possibility that initial kinetics of AFP under therapy have a prognostic value for estimating the quality of outcome.