Correspondence

Maternal and Fetal Thyroid Function

N Engl J Med 1995; 332:613-614March 2, 1995

Article

To the Editor:

The article by Burrow et al. on maternal and fetal thyroid function (Oct. 20 issue)1 was enlightening, but the authors did not address the possible effect on fetal thyroid function of antithyroid peroxidase (microsomal) antibodies in women with chronic autoimmune thyroiditis. Could transplacental passage of maternal antithyroid peroxidase antibodies damage fetal thyroid tissues? If so, should women with hypothyroidism, especially of recent onset, be tested for these antibodies before or during pregnancy?

Jack L. Snitzer, D.O.
19 Franklin St., Cambridge, MD 21613

1 References

1. 1

   Burrow GN, Fisher DA, Larsen PR. Maternal and fetal thyroid function. N Engl J Med 1994;331:1072-1078
   Full Text | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: Dr. Snitzer raises the possibility that maternal antithyroid microsomal antibodies might damage the fetal thyroid gland. Substantial amounts of maternal immunoglobulins do not cross the placental barrier before the third trimester, and there is no correlation between the presence of maternal serum antithyroglobulin or antiperoxidase antibodies and congenital hypothyroidism.1 Notwithstanding a few case reports,2-4 there is no evidence that maternal antithyroid antibodies have a role in most cases of sporadic congenital hypothyroidism.5 We see no reason to test for these antibodies in women with chronic autoimmune thyroiditis before or during pregnancy.

Gerard N. Burrow, M.D.
Yale University School of Medicine, New Haven, CT 06520-3055

Delbert A. Fisher, M.D.
Corning Nichols Institute, San Juan Capistrano, CA 92690

P. Reed Larsen, M.D.
Harvard Medical School, Boston, MA 02115

5 References

1. 1

   Dussault JH, Letarte J, Guyda H, Laberge C. Lack of influence of thyroid antibodies on thyroid function in the newborn infant and on a mass screening program for congenital hypothyroidism. J Pediatr 1980;96:385-389
   CrossRef | Web of Science | Medline

2. 2

   Sutherland JM, Esselborn VM, Burket BL, Skillman TB, Benson JT. Familial nongoitrous cretinism apparently due to maternal antithyroid antibody: report of a family. N Engl J Med 1960;263:336-341
   Full Text | Web of Science | Medline

3. 3

   Blizzard RM, Chandler RW, Landing BH, Pettit MD, West CD. Maternal autoimmunization to thyroid as a probable cause of athyrotic cretinism. N Engl J Med 1960;263:327-336
   Full Text | Web of Science | Medline

4. 4

   Goldsmith RE, McAdams AJ, Larsen PR, McKenzie M, Hess E. Familial autoimmune thyroiditis: maternal-fetal relationship and the role of generalized autoimmunity. J Clin Endocrinol Metab 1973;37:265-275
   CrossRef | Web of Science | Medline

5. 5

   Brown RS, Keating P, Mitchell E. Maternal thyroid-blocking immunoglobulins in congenital hypothyroidism. J Clin Endocrinol Metab 1990;70:1341-1346
   CrossRef | Web of Science | Medline