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Lazarus et al., Cardiff, Wales, UK, measured FT4 and
TSH in 219 TPOAb positive and 148 TPOAb negative pregnant women at approximately
12-14 weeks of gestation. They found abnormal thyroid function (hypo- or
hyperthyroidism) in 20.1% of TPO Ab positive women as compared to 6.8%
in TPO Ab negative women. The authors stress that abnormal thyroid function
in the mother may have adverse effects on the development of the neonate.
(Comment: Thyroid function should be monitored in TPOAb positive pregnant
women throughout pregnancy!)
Rodien et al., Brussels, Belgium, and Paris, France, report an interesting case of a woman suffering from recurrent gestational thyrotoxicosis lasting beyond the second trimester and sufficiently severe to require antithyroid drug treatment throughout pregnancy. After delivery, thyroid function returned to normal. It appeared that a mutation was present in the TSH receptor of the mother that, upon in vitro testing, was more sensitive to stimulation by hCG than the normal TSH receptor. Thus, a new entity is described in this report in that another cause of non-autoimmune hyperthyroidism is due to a mutation in the TSH receptor that renders it more than normal sensitive to human chorion gonadotrophin. (Comment: Thus, germline mutations in the TSH receptor may lead to hypothyroidism, hyperthyroidism due to constitutive stimulation of the cyclic AMP pathway, or [in this case] rendering it more sensitive to hCG. Furthermore, somatic mutations may lead to formation of autonomously functioning nodules.) |
