The thyroid is a gland responsible for regulating the body's metabolism. This metabolic control is carried out by thyroid hormones, which are made up of triiodothyronine (T3) and thyroxine (T4), and these in turn are controlled from a gland (pituitary gland) in the head by thyroid stimulating hormone (TSH).
Depending on whether this gland produces an excess or a deficit, we speak of hyperthyroidism or hypothyroidism. This condition is much more common in women than in men, and hypothyroidism is more common than hyperthyroidism.
The main symptoms of hyperthyroidism (overactivity of the thyroid gland) would be:
- Increased heart rate.
- Weight loss.
- Trembling of the hands.
As mentioned above, the thyroid gland's main function is to regulate metabolic processes. These include protein production, oxygen consumption and sensitisation to different male hormones, and elevated thyroid hormone levels can affect sperm maturation and formation (spermatogenesis) and sperm quality. In addition, the concentration of available free testosterone is reduced, increasing problems with sexual intercourse, e.g. premature ejaculation.
Most men who suffer from hyperthyroidism are classically diagnosed with abnormal sperm morphology, but sperm motility, volume, etc. may also be affected, so there is a strong possibility that it is interfering with a man's fertility.
Treatment of hyperthyroidism is supervised by an endocrinologist and is usually successful in reversing the deleterious effects of the disease on spermatogenesis.
If hormone levels are not restored after treatment, the best option for the couple to achieve pregnancy is to resort to one of the assisted reproduction techniques, such as in vitro fertilisation (IVF) or artificial insemination (AI).
