Home » Health & Wellness » Thyroid Disease » Hypothyroidism during Pregnancy effects IQ Scores

Hypothyroidism during Pregnancy effects IQ Scores

© Keri

A study published in the August 19, 1999 issue of The New England Journal of Medicine, concluded that undiagnosed hypothyroidism (underactive thyroid) in pregnant women may adversely effect their children’s intellectual performance and possibly increase difficulties in school.

The study conducted by Haddow, et al, screened stored blood samples from 25,216 women collected between 1987 and 1990. They identified 62 women with high levels of TSH indicating an underactive thyroid and matched them with 124 women with normal levels. These women were selected to have the same age, level of education, week of blood sampling during pregnancy, gender of the child and the duration of blood sample storage before testing. In this way, they tried to ensure the comparability of controls with the hypothyroid women.

The researchers then conducted a battery of tests on each 7 to 9 year old child. The scores of the children of hypothyroid women were an average of 4 points lower on the Wechsler Intelligence Scale for Children, third edition (107 for controls, 103 for hypothyroid). Fifteen percent scored at 85 or less compared with five percent of the controls. Forty-eight women identified as hypothyroid received no treatment during pregnancy. Those children averaged 7 points lower than controls with 19% scoring 85 or less. They concluded that screening for thyroid deficiency during pregnancy might be warranted.

This study should prompt further research to confirm these findings and study the impact of routine thyroid function screening during early pregnancy. The truth is, in today’s healthcare market, they must take into account the potential benefits and costs of such screening for mothers, their children and society as a whole. It is a sad reflection that cost drives care. In this study, less than 1% of the women were identified as hypothyroid.

The American Thyroid Association in a recent press release regarding this study recommended that:

 The decision about whether and when to assess thyroid function in a woman of childbearing age should be left to the judgments of the individual women and their doctors.

 Women of any age with new, persistent, or multiple symptoms of hypothyroidism (such as unexplained fatigue, intolerance of cold temperatures, constipation, dry skin, mental slowing and depression) should be screened for hypothyroidism.

 Women with previous thyroid disease or treatment, a family history of thyroid disease or enlargement of the thyroid gland (goiter) should be considered at particularly high rist.

 When it is appropriate to evaluate a woman’s thyroid status, the TSH blood test is recommended as the procedure of choice.