[Dysthyroidism and fertility].

The role of the thyroid gland in sterility is not well known; hyperthyroidism may have an effect upon estrogen secretion by decreasing the level of the free forms of estradiol, resulting in a lowering or disappearance of the LH ovulatory peak. Clinically, severe hypothyroidism would cause a retarded sexual development but simple hypothyroidism and hyperthyroidism do not seem to have a major effect upon sexual maturity. During the period of genital activity, hyperthyroidism may result in amenorrhea and dysovulation phenomena reminding of ovarian dystrophy; hypothyroidism results in the same phenomena, with decreased libido, but with a better screening process and a better adjusted substitute treatment, these disorders are rare. Finally, systematic evaluation of the thyroid function in unexplained sterilities, appears unnecessary most of the time.