Abstract
Antithyroid drugs, considered the treatment of choice for hyperthyroidism during pregnancy, may have an adverse effect on intellectual development of the offspring. We examined the intellectual capacity of 31 subjects aged 4–23 years, born to women with Graves disease who received antithyroid drugs throughout pregnancy. Methimazole 40–140 mg/week (n=15) or propylthiouracil 250–1400 mg/week (n=16) was given. I.Q. was assessed using the Wechsler test appropriate for age. Twenty-five unexposed siblings served as controls. The exposed and unexposed groups did not differ with respect to the total I.Q. Both groups scored equally in verbal and performance skills and in each of six main subcategories of the tests. There was no difference between exposure to methimazole and propylthiouracil or between the higher (>40 mg/week and >600 mg/week, respectively) and lower dosages. All children were euthyroid at birth and none had goitre. We conclude that exposure to methimazole or propylthiouracil during pregnancy in doses sufficient to control maternal hyperthyroidism does not pose any threat to intellectual capacity of the offspring.
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Abbreviations
- ATD:
-
antithyroid drugs
- MMI:
-
methimazole
- PTU:
-
propylthiouracil
References
Burrow GN, Bartsocas C, Klatskin EH, Grunt JA (1968) Children exposed in utero to propylthiouracil Am J Dis Child 116:161–165
Burrow GN, Klatstin EH, Genel M (1978) Intellectual development in children whose mothers received propylthiouracil during pregnancy. Yale J Biol Med 51:151–156
Cheron RG, Kaplan MM, Larsen PR, Selenkow HA, Crigler JF (1981) Neonatal thyroid function after propylthiouracil therapy for maternal Graves' disease. N Engl J Med 304:525–528
Cooper DS (1984) Antithyroid drugs. N Engl J Med 311:1353–1361
Cooper DS, Goldminz D, Levin AA, Ladenson PW, Daniels GH, Molitch ME, Ridgway EC (1983) Agranulocytosis associated with antithyroid drugs: effects of patient age and drug dose. Ann Intern Med 98:26–29
Daneman D, Howard NJ (1980) Neonatal thyrotoxicosis: intellectual impairment and craniosynostosis in later years. J Pediatr 97:257–259
Marchant B, Brownlie BEW, Hart DW, Horton PW, Alexander WD (1977) The placental transfer of propylthiouracil, methimazole and carbimazole. J Clin Endocrinal Metab 45:1187–1193
McCarroll AM, Hutchinson M, McAuley R, Montgomery DAD (1976) Longterm assessment of children exposed in utero to carbimazole. Arch Dis Child 51:532–536
Mestman JH (1974) Hyperthyroidism and pregnancy. Arch Intern Med 134:434–439
Momotani N, Noh J, Oyanagi H, Ishikawa N, Ito K (1986) Antithyroid drug therapy for Graves' disease during pregnancy. Optimal regimen for fetal thyroid status. N Engl J Med 315:24–28
New England Congenital Hypothyroidism Collaborative (1984) characteristics of infantile hypothyroidism discovered on neonatal screening. J Pediatr 104:539–544
Stephan MJ, Smith DW, Ponzi JW, Alden ER (1982) Origin of sclap vertex aplasia cutis. J Pediatr 101:850–853
Vulsma T, Gano MH, Vijlder JJM de (1989) Maternal-fetal transfer of thyroxine in congenital hypothyroidism due to a total organification defect or thyroid agenesis. N Engl J Med 321:13–16
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Eisenstein, Z., Weiss, M., Katz, Y. et al. Intellectual capacity of subjects exposed to methimazole or propylthiouracil in utero. Eur J Pediatr 151, 558–559 (1992). https://doi.org/10.1007/BF01957719
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DOI: https://doi.org/10.1007/BF01957719