Thyroid function in human pregnancy. IX. Development or retardation of 7-year-old progeny of hypothyroxinemic women.

Progeny of women, whose thyroid function was studied gestationally, had psychological and/or neurologic examinations at 8 months, 4 years and 7 years of age. In more than 100 pregnancies (at least 3 per cent of total pregnancies) hypothyroxinemia occurred and was treated adequately or inadequately. Children were delivered after uncomplicated pregnancies (except hypothyroxinemia), had birth weights of at least 2,500 grams, and were excluded when postnatal insults intervened. At 8 months and 4 years progeny of inadequately treated hypothyroxinemic women had the lowest psychological scores. Now 246 7-year-old children have been examined psychologically and neurologically (earlier data on only 101). Definite trends and a few statistically lower psychological scores of progeny of inadequately treated hypothyroxinemic pregnant women are compared with better psychological scores of 7-year-old children born to euthyroid and adequately treated hypothyroxinemic women. In six sibling sets outcome was better when hypothyroxinemic women were treated with adequate thyroid replacement therapy. If a woman has a poor reproductive history, early in a subsequent gestation, thyroid status should be examined and adequate thyroid medication considered seriously.